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GC864 Hardware User Guide

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2. 39 Ses M R616 oS i ATK mom i 77 DECOUPLING CAPACITORS END a U02 m A SRE e o 4 15349121D 2t a 15K vt i BES m v EE i ha 2 ne 2g z SD C527 R6145 mo LE __ 100m 47k T 1 1 Er un to i E FROM 1 03 GE863 MIC m i to 33v o Ww ee R ty So GND ann a UBD m A T53VB1210 Ed r ma o 15K oT ase E a EE IT 4 po FI 150K This circuit has a gain of 10 times 20 dB and is therefore suited for the Mic MT input if you have a microphone with a sensitivity close to the suggested one 45 dBV msPa If your microphone has a different sensitivity or if the buffer is connected to the Mic HF inputs then a gain adjustment shall be done by changing resistors R604 and R606 if the required value is not a standard one you can change R605 e R607 and as a consequence the capacitors C636 and C637 to maintain the bandwidth 150 4000Hz at 3dB Se B Reproduction forbidden without Telit Communications S p A written authorization All Right page 41 of 73 Z e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 The buffer gain is given by the formula R604 R606 Gain R605 R607 The C636 and C637 capacitors are placed in order to cut off the gain at higher frequencies than the transmitted GSM band the cutoff frequency 3dB should b
3. L7 5 1 Power Supply Requirements reo ce erret so reote pereo GANANG GAGANA 17 5 2 General Design Rules e C 18 52 1 Electrical Deston G idelM s eo di os 18 52 1 1 5V input Source Power Supply Design Guidelines ooocnnconncnonaconononnconnnnnononononnnnnonnnnnonnnn eene 18 5 2 1 2 12V Input Source Power Supply Design Guidelines essere 19 5 2 1 3 Battery Source Power Supply Design Guidelines eese 20 5 2 1 4 Battery Charge control Circuitry Design Guidelines ooooncncnnnnnonnnononcnnconnnnnoronononnnononnco non eene 21 5 2 2 Thermal Design Guideline Sinsice do dd on lobo He ase 22 5 2 3 Power Supply PCB layout Guidelines a nna GG e iae aE E aE Ese di 23 MEN terc EAEE AA AA 6 1 GSM Antenna Requirements oici csccisescscesssescseseesssccsssesseccesecveeessseceecassescetesescedstesucsesdeesanseesvecesecssenasves 24 6 2 GSM Antenna Installation Guidelines cscccsscssssssssccsscencecesssssssessesscssseseesscsscsssseneesesesseners 25 Eo No c 20 7 1 R5S232 level CUEDU RR 28 7 20 5VUART level translation ce0ce sees esses seen eene seen sentent sorore enne ta stesso neta sets sons ense ta RSKS Essos sasas 30 Ted TADA AO TANANG GARY GERA NENA 31 S Audio Sechon OTETVIEW NGA KENA OL 8 1 Microphone Paths Characteristic and Requirements
4. scsscscssscssscsscecssssscsssssecsssscsssssssesseseses 34 8 2 General Design Rules RE 37 8 3 Other considerations aeree eese esee eene enses enata sons tosta sesso se tastes sone toss nessi oep Usou Kord noo nono rcc naco conos 37 8 4 Microphone Biasing eere erce rosa eroe tro serra rose tbe o eb etes Po ER TURPE ERE SERE SURE SP PE RS PE E REESE PPS SEE OSEE sees seas soessscosevossoes 38 84 1 Balanced Microphone Biasit g haa ALAN rtt en ao date 38 8 4 3 Unbalanced Microphone Biasing sees enne enne enne teen nene rre innere nnne rennen innen 39 Aa eos Reproduction forbidden without Telit Communications S p A written authorization All Right Cd mn page of 73 Z e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 8 5 Microphone Buffering DR 41 831 Buffered Balanced Mic NN ERE Rs NA RN halang 41 8 5 2 Buffered Unbalanced Single Ended Microphone essesssesssesecseeeeeseesceaecetesecaeeseceaeeecaeeeeeaesaeeseeseseeeeaees 43 9 OUTPUT LINES Speaker nessosro iive FEPE e ERERRPREVEAREREERPERVPEEEL EFE FER UAP BIGAA 46 SS NA O 46 92 Output Lines Characteristics rettet eo to tetto tetro tes eto peto Seen Inn BRAKE 47 9 3 General BRITAIN Rs aiasidnd 48 SN A O 48 9 4 Handset Earphone Desigiics ccsc cciccsccccsosceosceosseossesssossseesseesssesssoossscuesssesosssecsesenssssesesossscsesnsdecssessoossvoss soe 49
5. 9 6 Car Kit Speakerphone Design For the car kit speaker phone function the power output requirement is usually at least 4W therefore an amplifier is needed to boost the GC864 QUAD PY output The design of the amplifier shall comply with the following guidelines e The input to the amplifier MUST be taken from the Ear HF audio path of the GC864 QUAD PY because of its echo canceller parameters suited to a car cabin use e The amplifier shall have a gain of 30 40 times 29 32 dB to provide the desired output power of 5 10W with the signal from the GC864 QUAD PY Ear HF audio output lines e If the amplifier has a fixed gain then it can be adjusted to the desired value by reducing the input signal with a resistor divider network e The amplifier shall have a mute control to be used while not in conversation This results in two benefits eliminating the background noise when not in conversation and saving power e The power to the amplifier should be decoupled as much as possible from the GC864 QUAD PY power supply by either keeping separate wires and placing bypass capacitors of adequate value close to the amplifier power input pads e The biasing voltage of the amplifier shall be stabilized with a low ESR e g a tantalum capacitor of adequate value NOTE The GC864 QUAD PY audio path connected to the car kit hands free amplifier MUST be Ear HF one otherwise the echo cancellation will not be done due to the difference i
6. see photo dimension where 38900 is the file dimension in bytes of the photo taken download the photo where data Correspond to the photo data in binary Repeating photo capture and download n times camera OFF page 68 of 73 lelit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 13 2Mounting the GC864 on your board The position of the Molex board to board connector and the pin 1 are shown in the following picture y Reproduction forbidden without Telit Communications S p A written authorization All Right reserved page 69 of 73 e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 13 3Packing system The Telit GE864 and GC864 are packaged on trays of 20 pieces each This is especially suitable for the GE864 according to SMT processes for pick amp place movement requirements ERN KOI i a Ju Wi JA P 44 gd i P NG Jo RU jg Hee T P mE Y d A Je Tr Egit Pa CAT UL rou f nir o raap Section A A The size of the tray is 329 x 176mm NOTE that trays can withstand at the maximum temperature of 65 C Reproduction forbidden without Telit Communications S p A written authorization All Right reserved page 70 of 73 Z e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 14 Conformity Assessment Issues The GC864 QUAD PY module is assessed to be conform to the R amp TTE Directive as stand
7. E be ALO a 2 1F5 T3405 Wiusional QO Wo Reset Signal Operating levels Signal Min Max RESET Inputhigh 2 2V 3 3V RESET Input low OV 0 2V this signal is internally pulled up so the pin can be left floating if not used Reproduction forbidden without Telit Communications S p A written authorization All Right reserved page 16 of 73 Y Z e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 o Power Supply The power supply circuitry and board layout are a very important part in the full product design and they strongly reflect on the product overall performances hence read carefully the requirements and the guidelines that will follow for a proper design 5 1 Power Supply Requirements The GC864 QUAD PY power requirements are e Nominal Supply Voltage 3 8V e Max Supply Voltage 42V e Supply voltage range 34V 42V e Max Peak current consumption impulsive 1 9A e Max Average current consumption during GPRS transmission rms 500 mA e Max Average current consumption during VOICE CSD transmission rms 270 mA e Average current during Power Saving z4mA e Average current during idle Power Saving disabled z 19 mA The GSM system is made in a way that the RF transmission is not continuous else it is packed into bursts at a base frequency of about 216 Hz the relative current peaks can be as high as about 2A Therefore the power supply has to be designed in order to withstand wit
8. device shall be placed into tristate disconnected or as a gateway for the serial data when module reprogramming occurs Only RXD TXD GND and the On off module turn on pad are required to the reprogramming of the module the other lines are unused All applicator shall include in their design such a way of reprogramming the GC864 v Reproduction forbidden without Telit Communications S p A written authorization All Right reserved page 28 of 73 Z e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 An example of level translation circuitry of this kind is U1 13v ICL3207CA SS0P 24 mu m rc QI ox oO LO 10 vee 2 CS O eo NG alo O o EN 12 14 C1 vt valey ma Oo 7 13 e r a ac m x u oy Gat a 1 c dato O Soo B 14 15 Cen NG oa e m Das o SER 77 7 2 GND dcd_uart gt T1 IN TA OUT DCD RS232 5 3 tx uart O 4 T2 1N T2 QUT DO TX RS23 18 1 dsr uart 2 34 13 IN TAS_OUT gt DSA_AS292 18 24 cts_uart LO 14 1N T4 QUT CTS R5232 21 20 ri uart 2 18 IN T5 OUT RI HS239 5 4 rx uart lt PI DUT BILIN BRx R8232 22 23 rts uart C R2 0UT R2 IN RTS R8232 17 15 dtr_uart lt _ P3 DUT ASIN DTR RS238 GND B B END the RS232 serial port lines are usually connected to a DB9 connector with the following l
9. 09 06 1 Overview The aim of this document is the description of some hardware solutions useful for developing a product with the Telit GC864 QUAD PY module In this document all the basic functions of a mobile phone will be taken into account for each one of them a proper hardware solution will be suggested and eventually the wrong solutions and common errors to be avoided will be evidenced Obviously this document cannot embrace the whole hardware solutions and products that may be designed The wrong solutions to be avoided shall be considered as mandatory while the suggested hardware configurations shall not be considered mandatory instead the information given shall be used as a guide and a starting point for properly developing your product with the Telit GC864 QUAD PY module For further hardware details that may not be explained in this document refer to the Telit GC864 QUAD PY Product Description document where all the hardware information is reported NOTICE EN The integration of the GSM GPRS GC864 QUAD cellular module within user application shall be done according to the design rules described in this manual 1T L integrazione del modulo cellulare GSM GPRS GC864 QUAD alf interno dell applicazione dell utente dovr rispettare le indicazioni progettuali descritte in questo manuale DE Die Integration des GC864 QUAD GSM GPRS Mobilfunk Moduls in ein Ger t mu gem der in diesem Dokument beschriebenen Konstrukti
10. 2p Ro ERU pd rape Atala nad 60 IE V erbonid dd e E 61 12 2 1 Description oae NN 61 12 2 2 Using ADC Converter secre eese etie hd eee eaa ee KGG BURA picas 61 13 Camera BABABA BISDAK NAGNIAS 62 13 1 AS sces suaveccssbevsavsseussdedsesssveasvevecuosesesdveeetesdsassezeed 62 13 1 1 Camera Interface Connectors cccccccsccessecesscecsseceececsseceseeecsseseceecsaeceeeecsseseeeeecsaeeeeseecsaeeeeaeecesuesseeeeesaeensees 63 13 12 EVB for Transchip C mera support erint tn dai anal 65 eos Reproduction forbidden without Telit Communications S p A written authorization All Right reserved page 4 of 73 PA e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 13 1 3 Block Diagram for supported cameras ooccoocccoccnononnnononnnononncononnnonnnn conc on rennen enne nennen trennt neen enne nre nein neenne 66 13 1 4 Schematic Diagrams for supported camera essent emen ennen nena rn anne nn enne 67 13 1 5 Example usage script for camera neret ener eneenren nennen ne enne trennen ete te en nan ener enne 68 13 2 Mounting the GC864 on your board eee eee ee anes ee ette seen seta seta setas etna e tassa asta se esee eee sesso see 69 EXCUSA AAA me AR no o Sivir k ost risoto sses sE ose 70 14 Conformity Assessment ISSUES os ssosssscsssesssocesoosscosssocessecesocesocssoossscosesocessocesocssoosssoesssecssocssooses 71 15 SAFETY RECOMMANDATIONS eeseesescesoesessosseseosossesoosossoss
11. 32 C109 DCD O Output for Data carrier detect signal DCD to DTE CMOS 2 8V IIC EN cc O Camera IIC interface Configurable GPIO CMOS 2 8V 36 TEE lO Camera IIC interface Configurable GPIO CMOS 2 8V DAC and ADC 37 ADC IN1 Al Analog Digital converter input A D 38 ADC IN2 Al Analog Digital converter input A D 39 ADC_IN3 Al Analog Digital converter input A D 40 DAC_OUT AO Digital Analog converter output D A Miscellaneous Functions 44 MON1 CAM l O MON1 Camera interface CMOS 2 8V 45 STAT LED O Status indicator led CMOS 1 8V 46 GND Ground Ground 49 PWRMON O Power ON Monitor CMOS 2 8V 50 VAUX1 Power output for external accessories 51 CHARGE Al Charger input Power 52 CHARGE Al Charger input Power Input command for switching power ON or OFF toggle commana 53 ON OFF l The pulse to be sent to the GC864 must be equal or greater than 1 47K Pull up to VBATT second 54 RESET Reset input 55 VRTC AO VRTC Backup capacitor Power Telit GPIO 56 TGPIO 19 I O Telit GPIO19 Configurable GPIO CMOS 2 8V 57 TGPIO_11 I O Telit GPIO11 Configurable GPIO CMOS 2 8V 58 TGPIO_20 I O Telit GPIO20 Configurable GPIO CMOS 2 8V 59 TGPIO 04 I O Telit GPIO4 Configurable GPIO CMOS 2 8V 60 TGPIO 14 I O Telit GPIO14 Configurable GPIO CMOS 2 8V 61 TGPIO 15 I O Telit GPIO15 GPIO pin CMOS 2 8V I Mi Reproduction forbidden without Telit Communications S p A written authorization All Right reserved page of 73 Z e Telit GC864 Hardware User Guide
12. Base Band Chip of the GC864 QUAD PY Telit Module provides two different audio blocks both in transmit Uplink and in receive Downlink direction MT lines should be used for handset function HF lines is suited for hands free function car kit These two blocks can be active only one at a time selectable by AXE hardware line or by AT command The audio characteristics are equivalent in transmit blocks but are different in the receive ones and this should be kept in mind when designing Reproduction forbidden without Telit Communications S p A written authorization All Right reserved page 32 of 73 PA e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 audio2 skd EXTERNAL AMPLIFIER ie i Fully Differential Power Buffers Balanced Line Out Drivers Differential Audio Paths page 33 of 73 PA Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 8 1 Microphone Paths Characteristic and Requirements TIP being the microphone circuitry the more noise sensitive its design and layout must be done with particular care Both microphone paths are balanced and the OEM circuitry should be balanced designed to reduce the common mode noise typically generated on the ground plane However also an unbalanced circuitry can be used for particular OEM application needs TIP due to the difference in the echo canceller type the Mic MT a
13. Hardware shutdown To turn OFF the GC864 QUAD PY the pad ONF must be tied low for at least 2 seconds and then released The same circuitry and timing for the power on shall be used The device shuts down after the release of the ONF pad TIP To check if the device has powered off the hardware line PWRCTL should be monitored When PWRCTL goes low the device has powered off 4 2 2 Hardware Unconditional Restart To unconditionally Restart the GC864 QUAD PY the pad RESET must be tied low for at least 200 milliseconds and then released The maximum current that can be drained from the ON pad is 0 15 mA A simple circuit to do it is RESET Unconditional Restart N E E i impulse TAN t V yoo 77 GND page 15 of 73 Z e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 NOTE don t use any pull up resistor on the RESET line nor any totem pole digital output Using pull up resistor may bring to latch up problems on the GC864 QUAD PY power regulator and improper functioning of the module The line RESET must be connected only in open collector configuration TIP The unconditional hardware Restart should be always implemented on the boards and software should use it as an emergency exit procedure For example 1 Let s assume you need to drive the RESET pad with a totem pole output of a 3 5 V microcontroller UP OUT2 RESET
14. R718 of 470KQ TIP example of calculation Llet s assume you have a microphone with a sensitivity of 45dBV m Pa and you want to use it in 2nd differential microphone path Mic HF inputs in normal spoken conditions at acoustic pressure of 4 7dBPa As reported at page XX the electrical level output from the microphone will be MicLevel 45 4 7 49 7 dBV ms but we have to consider 20dB loss due to the higher distance from the mouth of the talker 50cm MicLevel 49 7 20 69 7 dBV ms corresponding to MicVoltage 10 997 9 33 10 In order to have a signal of 1 mV 4 at the Mic HF inputs as suggested at TIP environment consideration the buffer must have a gain G4 Mic HF MicVoltage 1 10 3 0 33 10 3 3 or 10 dB Keeping in mind that balancing the line will double the signal to calculate the resistor values assign half of required gain Ga to each amplifier section And therefore Gs 1 5times or 3 52dB Choosing as 10kQ as the input resistance the corresponding values for the resistors on the buffer will be R711 Gs R708 1 5 10 15 kQ R719 Gs 1 R720 1 5 1 10 5 kQ The commercial values of 15kQ and 5 6kQ be accepted page 44 of 73 Z e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 As a consequence of the assigned values of the resistors the nominal values of C726 and C727 are C726 1 21 4000 R719 7 10
15. antenna s used for this transmitter must be installed to provide a separation distance of at least 20 cm from all persons and must not be co located or operating in conjunction with any other antenna or transmitter End Users must be provided with transmitter operation conditions for satisfying RF exposure compliance OEM integrators must ensure that the end user has no manual instructions to remove or install the GC864 QUAD PY module Antennas used for this OEM module must not exceed 3dBi gain for mobile and fixed operating configurations z Reproduction forbidden without Telit Communications S p A written authorization All Right reserved page 24 of 73 PA e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 6 2 GSM Antenna Installation Guidelines e Install the antenna in a place covered by the GSM signal e The Antenna must be installed to provide a separation distance of at least 20 cm from all persons and must not be co located or operating in conjunction with any other antenna or transmitter e Antenna shall not be installed inside metal cases e Antenna shall be installed also according Antenna manufacturer instructions Reproduction forbidden without Telit Communications S p A written authorization All Right reserved page 25 of 73 Z e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 7 Serial Port The serial port on the Telit GC864 is the core of the interface between the modu
16. overheating For the heat generated by the GC864 QUAD PY you can consider it to be during transmission 1W max during CSD VOICE calls and 2W max during class10 GPRS upload A AMERO qme E E Reproduction forbidden without Telit Communications S p A written authorization All Right reserved page 22 of 73 Z e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 This generated heat will be mostly conducted to the ground plane under the GC864 QUAD PY you must ensure that your application can dissipate it 5 2 3 Power Supply PCB layout Guidelines As seen on the electrical design guidelines the power supply shall have a low ESR capacitor on the output to cut the current peaks and a protection diode on the input to protect the supply from spikes and polarity inversion The placement of these components is crucial for the correct working of the circuitry A misplaced component can be useless or can even decrease the power supply performances e The Bypass low ESR capacitor must be placed close to the Telit GC864 QUAD PY power input pads or in the case the power supply is a switching type it can be placed close to the inductor to cut the ripple provided the PCB trace from the capacitor to the GC864 QUAD PY is wide enough to ensure a dropless connection even during the 2A current peaks e The protection diode must be placed close to the input connector where the power source is drained e The PCB traces from the input c
17. the GC864 QUAD PY is not enough or if the speaker characteristics are different from the suggested then it is preferable to use an amplifier to increase the power and current output capabilities Again the output from the GC864 QUAD PY is bridged and both lines should be used where possible as inputs to the power amplifier This ensures a higher common mode rejection ratio reducing the GSM current busts noise on the speaker output In this case the EAR MT lines from the GC864 QUAD PY should be AC coupled with a ceramic capacitor of 100nF or bigger It is always desirable to have a mute control on the amplifier in order to turn it off while the device is not sending signal to the output in this manner the amplifier background noise which may be audible during idle conditions is cut off A principle schematic may be le la lo LP H2 C3 JEAR MTt EAR QUT HOOnF HMOOnF C2 R1 1 RS JEAR MT vcc 2 E 1uF Y 47K 17 GND GND Se eos Reproduction forbidden without Telit Communications S p A written authorization All Right CJ page of 73 Z e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 The resulting gain and high pass cut can be obtained with the formula edt R2 req Hz freq y gasca L And an example of internal Ear amplifier could be INTERNAL EAR AMPLI
18. the device however also a single ended circuitry can be designed for particular OEM application needs Se ae Reproduction forbidden without Telit Communications S p A written authorization All Right CJ page of 73 9 2 Output Lines Characteristics Ear MT Differential Line out Drivers Path line coupling line type output load resistance internal output resistance signal bandwidth max differential output voltage differential output voltage SW volume level step number of SW volume steps Ear HF Power Buffers path line coupling line type output load resistance internal output resistance signal bandwidth max differential output voltage max single ended output voltage SW volume level step number of SW volume steps 4 e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 DC bridged 2140 4 Q typical 150 4000 Hz 3 dB 1310 mV rms typ open circuit 328mVrms 16 Q 12dBFS 2dB 10 DC bridged 2140 40 gt 1 70 150 4000 Hz 3 dB 1310 MV ms typ open circuit 656 MVims typ open circuit 2dB 10 As Reproduction forbidden without Telit Communications S p A written authorization All Right reserved page 47 of 73 Z e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 9 3 General Design Rules There are several configurations for the audio output path but the various design requirements can be grouped int
19. 1 07 09 06 NOTE In the unbalanced application the capacitor C3 shall be 200nF otherwise the frequency response will be cut at low band frequencies down to 300Hz This capacitor can be placed close to the MIC pad MIC HF or MIC MT depending on the audio path chosen or if possible it should be placed close to the shielded cable connector If the ground return path is well designed then it is possible to eliminate the C3 capacitor provided the buffer is close to the mic input NOTE The cable to the microphone should be shielded NOTE The microphone changes with the value of R2 Usually the microphone sensitivity is characterized with 2kQ biasing resistance so try to keep the value of R2 around 2kQ For mic characteristics refer to the manufacturer page 40 of 73 Z e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 8 5 Microphone Buffering As seen previously a microphone shall be connected to the input pins of the GC864 QUAD PY through a buffer amplifier that boosts the signal level to the required value Again the buffered microphone circuitry can be balanced or unbalanced where possible it is always preferable a balanced solution The buffering circuit shall be placed close to the microphone or close to the microphone wire connector 8 5 1 Buffered Balanced Mic A sample circuit can be BALANCED MICROPHONE BUFFER 20dB
20. 10 F C727 1 21 4000 R711 7 2 65 10 F modified in 6 8nF f 4181HZ and 2 7nF f 2 3931Hz because of commercial values Reproduction forbidden without Telit Communications S p A written authorization All Right reserved page 45 of 73 Z e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 9 OUTPUT LINES Speaker 9 1 Short description The Telit GC864 QUAD PY provides two audio paths in receive section Only one of the two paths can be active at a time selectable by AXE hardware line or by AT command You must keep in mind the different audio characteristics of the receive blocks when designing gt the Ear MT lines EPN1 and EPP1 are the Differential Line Out Drivers they can drive an external amplifier or directly a 16 Q earpiece at 12dBFS gt the Ear HF lines EPPA1 2 and EPPA2 are the Fully Differential Power Buffers they can directly drive a 162 speaker in differential balanced or single ended unbalanced operation mode FS acronym of Full Scale It is equal to OdB the maximum Hardware Analog Receive Gain of BaseBand Chip The Ear MT audio path should be used for handset function while the Ear HF audio path is suited for hands free function car kit Both receiver outputs are B T L type Bridged Tie Load and the OEM circuitry shall be designed bridged to reduce the common mode noise typically generated on the ground plane and to get the maximum power output from
21. 1vv0300733 Rev 1 07 09 06 Pin Signal 1 0 Function puel is Type 62 TGPIO 12 VO Telit GPIO12 Configurable GPIO CMOS 2 8V 63 TGPIO 10 VO Telit GPIO10 I O pin CMOS 2 8V 64 TGPIO 22 VO Telit GPIO22 Configurable GPIO CMOS 1 8V 65 TGPIO 18 lO Telit GPIO18 I O pin CMOS 2 8V 66 TGPIO 03 VO Telit GPIO3 Configurable GPIO CMOS 2 8V 67 TGPIO 08 CAM ON I O Telit GPIO8 Configurable GPIO Camera Interface CMOS 2 8V 68 TGPIO 06 ALARM I O Telit GPIO6 Configurable GPIO ALARM CMOS 2 8V 69 TGPIO 23 1 0 EVEN detect ON OFF It is physically connected to pin 49 CMOS 2 8V 70 TGPIO 01 VO Telit GPIO1 Configurable GPIO CMOS 2 8V 71 TGPIO 17 VO Telit GPIO17 GPIO pin CMOS 2 8V 72 TGPIO 21 VO Telit GPIO21 Configurable GPIO CMOS 2 8V 73 TGPIO 07 BUZZER W O Telit GPIO7 Configurable GPIO Buzzer CMOS 2 8V 74 TGPIO 02 JDR lO Telit GPI002 I O pin Jammer detect report CMOS 2 8V 75 TGPIO 16 O Telit GPIO16 Configurable GPIO CMOS 2 8V EM GPIO 09 MO Telit GPIO9 GPIO I O pin 7 Camera Interface CMOS 2 8V CAM RST 77 TGPIO 13 VO Telit GPIO13 Configurable GPIO CMOS 2 8V 78 PON MO Telit GPIO05 Configurable GPIO Transmitter ON monitor CMOS 2 8V RESERVED 17 33 E 34 41 E 42 43 2 47 E 48 E 79 80 i NOTE RESERVED pins must not be connected RTS should be connected to the GND on the module side if flow control is not used M Reproduction forbidden without Telit Communications S p A written authorization All Right reserved page 11 of
22. 73 VA Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 NOTE If not used almost all pins should be left disconnected The only exceptions are the following pins pin signal 1 2 3 4 GND 5 6 7 46 VBATT 25 TXD 26 RXD 31 RTS 53 ON OFF 54 RESET 3 1 1 GC864 Antenna connector The GC864 module is equipped with a 50 Ohm RF connector from Murata GSC type P N MM9329 2700B The counterpart suitable is Murata MXTK92 Type or MXTK88 Type Moreover the GC864 has the antenna pads on the back side of the PCB This allows the manual soldering of the coaxial cable directly on the back side of the PCB However the soldering is not an advisable solution for a reliable connection of the antenna y Reproduction forbidden without Telit Communications S p A written authorization All Right reserved page 12 of 73 Z e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 4 Hardware Commands 4 1 Turning ON the GC864 QUAD PY To turn on the GC864 QUAD PY the pad ON must be tied low for at least 1 seconds and then released The maximum current that can be drained from the ONF pad is 0 1 mA A simple circuit to do it is ON RI al mE RN r a N A 7 NK Q1 VV V LN Power ON impulse NI hy AN O R2 FTG AN NOTE don t use any pull up resistor on the ON line it is internally pulled up Using pull up resistor may bring to latch up problems on the GC864 QUAD P
23. 9 5 Hands Free Earphone Low Power Desigt sscssscssscssscssscsssscssssssssscssseesseessecssscssscsssccesscsseceses 50 9 6 Car Kit Speakerphone Design 0 0scccsccisessenssesssonssoessensscossesossvonesseescoescsesbnescnedenosseoseesvonsvoed maan 51 10 SIM DESIGN GUIDES ja BUNGANGA 52 10 1 A T oS 52 10 2 EMUEMOJ p3ng LIANAGGG 52 A A AA AA AA 53 10 4 SIM Supply aaa 53 10 5 SCHEMA MS op oc 53 10 6 LAYOUT 54 Il General Purpose AAA A 55 I Erud 56 11 2 Using a GPIO Pad as INPUT JENNIE ODIN KITAAN ENNA 57 11 3 Using a GPIO Pad as OUTPUT cnisccssiccsccsscosssocsssostsossasssevesesseonssosssocceosseasseestoassoassvesseecssoosestiesoseesosassoe 57 11 4 Using the Alarm Output GPIO6 eere eese eee seen esee eene esses ttes to ette seta seta seen setas e ease tasse eese testo aae 57 11 5 Using the Buzzer Output GPIOT 2NG eres rove eet ne ever erae ano rene Uo annee aS Ines era ere ape 57 12 DAC and Tecno c RN 59 12 1 INN 2410 59 12 1 1 Ib eap PE cc ee cae 59 12 1 2 Enabhng DAC pnr on ue Hd E eee MR NIE 59 12 1 3 Low Pass Filter Example
24. A1 F1 GND Ground 2 AGND r3 VAUX1 O Power Supply 3 AVDD28 l c9 CAM_RST O Camera Reset 4 RESET N l F8 MON1_CAM O Clock 5 CLK IN l A1 F1 GND Ground 6 DGND l ne nc 7 DOUTO 10 n c n c 8 DOUT 1 1 0 n c n c 9 DOUT 2 1 0 n c n c 10 DOUT 3 1 0 n c n c 11 DOUT_4 1 0 n c n c 12 DOUT 5 1 10 n c n c 13 DOUT 6 1 10 n c n c 14 DOUT_7 1 10 n c n c 15 DOUT 8 1 0 n c n c 16 VCLKOUT O n c n c 17 VALIDH O n c n c 18 VALIDV O D5 VAUX1 O Power Supply 19 DVDD28 l D7 CAM_SDA lO I2C bus serial data 20 SDIN 1 0 A1 F1 GND Ground 21 PS1 d 1 CAM ON O Camera power type selector 22 PS2 l A1 F1 GND Ground 23 SHIELD x Flash Enable 24 LED CTRL O Filter the AVDD28 _Use a Buffer between module clk out MON1 CAM and camera clk in CLK IN Non connected page 63 of 73 Z e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 Fig 1 Camera Physical Detail amp Connector 630 20 025 0 30 3003 SECTION A A d Dire DIMENSIONS mm 12 50 SECTION B B THX TD D GLASS PLASTIC WUSWALTON 55 544540 14 024 4 86 0 1 02 p 265 Fig 2 Camera Socket Connector p x RT No 20 Ligo aa 165 as io 192 us 195 120 114 Lio i23 mA 5 150 sas o 155 342 me Pe l 22 Reproduction forbidden without Telit Communications S p A written authorization All Right reserved page 64 of 73 Z e Te
25. ADC_IN1 available on Ball J11 and Pin 19 of PL104 on EVK2 Board CS1152 ADC_IN2 available on Ball H11 and Pin 20 of PL104 on EVK2 Board CS1152 ADC_IN3 available on Ball G11 and Pin 21 of PL104 on EVK2 Board CS1152 12 2 2 Using ADC Converter An AT command is available to use the ADC function The command is ATHADC 1 2 The read value is expressed in mV Refer to SW user guide or to GC864 QUAD PY AT commands specification for the full description of this function page 61 of 73 Z e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 13 Camera 13 1 Transchip Camera The GC864 QUAD PY provides a direct support for Transchip digital cameras with the following characteristics Type TRANSCHIP TC5747 Technology CMOS COLOR camera Max picture size VGA 480x640 pixels landscape Output format JPEG Sensitivity 4 Lux Reproduction forbidden without Telit Communications S p A written authorization All Right reserved page 62 of 73 Z e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 13 1 1 Camera Interface Connectors The pinout of the module and a 24 pins ZIF connector for the CMOS camera provide the interface connection between GC864 QUAD PY and Transchip camera GC864 QUAD PY signal TC5747MF24L Pin Signal 1 0 Notes Pin Signal y o C6 CAM SCL O 12C bus serial clock 1 SCLK l
26. Buffered Unbalanced Single Ended Microphone SINGLE ENDED MICROPHONE BUFFER 410 dB 33Y EXT MIG SINGLE ip 3V EXT MIC SINGLE Tes n 3768 R714 4 27128 47k i GND 1 BA 0603 a U704 GE863 af 153v912I1D TES m Mic m nrag DECOUPLING CAPACITORS Og n va o5 58 3 MS AG y presi be PS ind 3 2 m 4 zu O S 25nm i C7419 R716 eps m MIC sE 20 1 1DDnF 47k ene NG xS HE E 0 T i EL Es 1 1E w HA TOMIC oo oras osos E To 1 m 1 SN E om s ERU huksi GE863 Mie Ear os 22 f gt EEE i 1 GND BEND GNOD 1 1 434_EXT MIG SINGLE D a U701 D GE863 sa TS3vB121D ERRE Mic 7 oT TE i I tay EXT MIC SINGLE S ad y i i OT II M i i R747 R720 4 i i 10K fy Da B dc GNG Na 59 Ta ax ir a 0603 E m ROSE 0603 1 4 s 5 i C725 MEE m C720 R715 100nF Os 188 Ja 1 100nF AFK Yw 1 IL iby OLOR e ee cece oe Baa NG si 16v lah 0603 0603 0603 GNG GNG END The above schematic can be used for a single ended buffered unbalanced microphone the required biasing circuitry is not included Note also that the capacitor C3 is not needed The gains of the two amplifiers are given by the formulas R719 R720 R711 R708 Gain not inverting buffer 1 Gain inverting buffer Assig
27. E 9 8 Ot iT Glog E I Ne ue ion ES Hos E AT IHE 1 ii vives B i o fE Of Lp lj pa amp D T i D rro usa oll ne aaa a EE oru o IEA sur El lt Dem Sus oti gaal o Breras ae i Ty l8 d on ot pl D D 10m vena mm hame UT wis E l E s iride i Sin A LACE TBs wwa st poda gg i gt I l 131131 l nar G son y i igi 81 1 E ka E i PIL i or 5 s s r E z 1 Reproduction forbidden without Telit Communications S p A written authorization All Right reserved page 67 of 73 PA e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 13 1 5 Example usage script for camera Camera setting shown here are the defaults ones gt AT CAMSEL 0 OK gt AT CMODE 0 OK gt AT CAMQUA 0 OK gt AT CAMRES 0 OK gt AT CAMCOL 0 OK gt AT CAMZOOM 0 OK gt AT CAMT XT 0 OK Taking an reading a photo gt AT CAMEN 1 OK SAT TPHOTO OK gt AT OBJL OBJL Snapshot 38900 OK gt AT RPHOTO data OK SAT TPHOTO OK gt AT RPHOTO data OK gt AT CAMEN O only Transchip camera camera selection 0 auto 1 agilent 2 transchip camera mode 0 day 1 night camera quality O low 1 medieum 2 high camera resolution 0 VGA 1 QVGA 2 QQVGA camera color O color 1 grayscale camera zoom 0 x1 1 x2 2 x4 camera timestamp 0 no 1 time only 2 data only 3 time amp data camera ON take photo
28. FIER 12dB UBO1 13 70 LN4662M 1 1 1 1 1 1 1 1 1 1 1 1 1 i i 43 7 o 1 Ox Mez m H on 55 m s H TO SPEAKER 5 loan n L4 H o E 28 gt JE NT 5 i ping EAR CT KOS SHUTDDHN zr xD 1 a 2 of 48 Quz FROM GC864 QUAD PY EAR C3 vce BYPASS 08352 1 CB21 cB22 7 Jeno me L3 i 25 28 d jtm 4000F 100nF p vat i CB02 i 16v 16v 1000F 0603 0603 H hee C801 RE i 0603 me PL803 l Des 1815061 03F 1 0603 1 1 ABO ABOG qe d 15 Dr zl MUTE CONTROLLED 5 ES i ni nu en 3 __ LWAYE ON osoa 0603 h Wi e 1 1 END k L A 177 i n Some amplifier require a low impedance load at high frequency in order to avoid auto oscillation this can be made with a capacitor 100nF in series with a resistor 150 When designing your application remember to provide an adequate bypass capacitor to the amplifier and place it close to the power input pin of the IC keeping the traces as short as possible 9 5 Hands Free Earphone Low Power Design The same design considerations made for the handset are valid for the hands free earphone Li 5 P t li NG f ESA E Reproduction forbidden without Telit Communications S p A written authorization All Right reserved page 50 of 73 Z e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06
29. I f 5 2 1 2 12V Input Source Power Supply Design Guidelines e The desired output for the power supply is 3 8V hence due to the big difference between the input source and the desired output a linear regulator is not suited and shall not be used A switching power supply will be preferable because of its better efficiency especially with the 2A peak current load represented by the GC864 QUAD PY e When using a switching regulator a 500kHz or more switching frequency regulator is preferable because of its smaller inductor size and its faster transient response This allows the regulator to respond quickly to the current peaks absorption e For car PB battery the input voltage can rise up to 15 8V and this should be kept in mind when choosing components all components in the power supply must withstand this voltage e A Bypass low ESR capacitor of adequate capacity must be provided in order to cut the current absorption peaks a 100uF tantalum capacitor is usually suited e Make sure the low ESR capacitor on the power supply output usually a tantalum one is rated at least 10V e For Car applications a spike protection diode should be inserted close to the power input in order to clean the supply from spikes e A protection diode should be inserted close to the power input in order to save the GC864 QUAD PY from power polarity inversion This can be the same diode as for spike protection 143 C eos Reproduction forbidden wit
30. S e f leli wireless solutions GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 EN S 8 a Y etm LAN aW A A Making machines talk Z e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 This document is relating to the following products Model P N GC864 QUAD 3990250675 GC864 PY 3990250676 Reproduction forbidden without Telit Communications S p A written authorization All Right reserved page 2 of 73 Z e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 Contents 1 QV GL VIEW usi naGG AB BUNANBANBGNBUGIHGGEBEGSINGNIAGSNKGNBATINN RIA KINING 7 2 GC864 Mechanical DimensioNS oooooomomm D 3 GC864 module connectiONsS ooomomomms Y 3 1 A EEE 9 IFI ESO Antenna connector eee eee tette eret ev Loc etie da 12 4 Hardware Commands oocccccmommm LI 4 1 Turning ON the GC864 QUA D PY eee eee esee seen eee n6 seta a estan see G0 se eo se seen sese ea sesso se sn aset ense etant 13 4 2 Turning OFF the GC864 QUA D PY ecce eee eee eee sa eere seta aset an see to s so sa seen asse ease eese s eaae sense eaa 15 42 T lasdwareshutdOWt eo Eee e pes kin eo Exe e Lasa E EE ELORE EEEE EErEE ah tune spa nune 15 4 2 2 Hardware Unconditional Restalt oconoocuoncnnnononoconcnocononanannnonocnnnonnonononocononnn nnne seine ite tenen e EAEE errre eenen nesre terne ases 15 5 isdem e E
31. Y power regulator and improper power on off of the module The line ON must be connected only in open collector configuration NOTE In this document all the lines that are inverted hence have active low signals are labeled with a name that O ends with a or with a bar over the name NOTE The GC864 QUAD PY turns fully on also by supplying power to the Charge pad provided there s a battery D on the VBATT pads page 13 of 73 Z e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 For example 1 Let s assume you need to drive the ON pad with a totem pole output of a 3 5 V microcontroller uP OUTTX ON 5 6 32 uP_OUT 1 O BC847BW S T 323 Fs T3 8 4 ov cl L 1s Power ON OFF inpulse GND 2 Let s assume you need to drive the ON pad directly with an ON OFF button OND Reproduction forbidden without Telit Communications S p A written authorization All Right reserved page 14 of 73 4 e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 4 2 Turning OFF the GC864 QUAD PY The turning off of the device can be done in three ways e by software command see GC864 QUAD PY Software User Guide e by hardware shutdown e by Hardware Unconditional Restart When the device is shut down by software command or by hardware shutdown it issues to the network a detach request that informs the network that the device will not be reachable any more 4 2 1
32. a twisted pair with both the lines floating for the bridged output type shielded with the shield to ground for the single ended output type 9 3 1 Noise Filtering The I O of the PCB should have a noise filter close to the connector to filter the high frequency GSM noise The filter can be a M formed by 2 capacitor and a inductance with the one capacitor of 39pF 0603 case and the other capacitor of 1nF 0603 the inductance shall have a value of 39uH z Reproduction forbidden without Telit Communications S p A written authorization All Right reserved page 48 of 73 Z e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 9 4 Handset Earphone Design As seen previously a 160 earpiece can be directly connected to the output pads EAR MT and EAR MT of the GC864 QUAD PY This solution is often the more cost effective reducing the components count to a minimum There are several limitations to the use of this solution speaker direct connect imposes the speaker characteristics to be almost exactly the suggested ones otherwise the power output may be reduced if speaker impedance is bigger than 160 or the GC864 QUAD PY ear port may be damaged if speaker impedance is less than 150 The other limitation of the speaker direct connection is the power output capability of the GC864 QUAD PY which is limited and for some particular applications may not be enough For these reasons when the power output of
33. alone products so If the module is installed in conformance with Dai Telecom installation instructions require no further evaluation under Article 3 2 of the R amp TTE Directive and do not require further involvement of a R amp TTE Directive Notified Body for the final product In all other cases or if the manufacturer of the final product is in doubt then the equipment integrating the radio module must be assessed against Article 3 2 of the R amp TTE Directive In all cases assessment of the final product must be made against the Essential requirements of the R amp TTE Directive Articles 3 1 a and b safety and EMC respectively and any relevant Article 3 3 requirements The GC864 QUAD PY module is conform with the following European Union Directives e R amp TTE Directive 1999 5 EC Radio Equipment amp Telecommunications Terminal Equipments e Low Voltage Directive 73 23 EEC and product safety e Directive 89 336 EEC for conformity for EMC In order to satisfy the essential requisite of the R amp TTE 99 5 EC directive the GC864 QUAD PY module is compliant with the following standards e GSM Radio Spectrum Standard EN 301 511 and 3GPP 51 010 1 e EMC Electromagnetic Compatibility Standards EN 301 489 1 and EN 301 489 7 e LVD Low Voltage Directive Standards EN 60 950 In this document and the Hardware User Guide Software User Guide all the information you may need for developing a product meeting the R amp TTE Directive is inc
34. ation All Right reserved page 57 of 73 PA Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 This permits to your application to easily implement Buzzer feature with ringing tones or melody played at the call incoming tone playing on SMS incoming or simply playing a tone or melody when needed by your application Q102 s2F BZ101 SOT 23 SMUS 1227 SMBT2907A A sample interface scheme is included below to give you an idea of how to interface a Buzzer to the GPIOT NOTE To correctly drive a buzzer a driver must be provided its characteristics depend on the Buzzer and for them refer to your buzzer vendor Reproduction forbidden without Telit Communications S p A written authorization All Right reserved page 58 of 73 Z e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 12 DAC and ADC section 12 1DAC Converter 12 1 1 Description The GC864 QUAD PY module provides a Digital to Analog Converter The signal named DAC OUT is available on BGA Ball C7 of the GC864 QUAD PY module and on pin 17 of PL104 on EVK2 Board CS1152 The on board DAC is a 10 bit converter able to generate a analogue value based a specific input in the range from O up to 1023 However an external low pass filter is necessary Min Max Units Voltage range filtered 0 2 6 Volt Range 0 1023 Steps The precision is 10 bits so if we consider that the maximum voltage is 2V the integrated voltag
35. ayout DCD AS232 DSR RS232 a 2 TX RS232 S C ro RTS PSses2 e RX RS232 O Ju CTS_AS232 O DTR Rs2e32 On RI RS232 O O pa Al GN Mm 3 Reproduction forbidden without Telit Communications S p A written authorization All Right reserved page 29 of 73 Z e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 7 2 5V UART level translation If the OEM application uses a microcontroller with a serial port UART that works at a voltage different from 2 8 3V then a circuitry has to be provided to adapt the different levels of the two sets of signals As for the RS232 translation there are a multitude of single chip translators but since the translation requires very few components then also a discrete design can be suited For example a possible inexpensive translator circuit for a 5V driver can be BCR22PN WPS 501 363 TO TxD 5v C FROM OEM GM862 HARDWARE lt 1xD_3v ATK and for a 5V receiver C1034T20154 C FWRCTL Gi BCR22PN L5 c103 Txu 2 ay WPS 501 363 Reproduction forbidden without Telit Communications S p A written authorization All Right reserved page 30 of 73 PA Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 NOTE The UART input line TXD rx uart of the GC864 is NOT internally pulled up with a resistor so there may be the need to place an exte
36. between the input source and the desired output and a linear regulator can be used A switching power supply will not be suited because of the low drop out requirements e When using a linear regulator a proper heat sink shall be provided in order to dissipate the power generated e A Bypass low ESR capacitor of adequate capacity must be provided in order to cut the current absorption peaks close to the GC864 QUAD PY a 100uF tantalum capacitor is usually suited e Make sure the low ESR capacitor on the power supply output usually a tantalum one is rated at least 10V e A protection diode should be inserted close to the power input in order to save the GC864 QUAD PY from power polarity inversion Se ae Reproduction forbidden without Telit Communications S p A written authorization All Right CJ page of 73 Z e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 An example of linear regulator with 5V input is t5v input linear regulator I E l I I E l l l l l I I I I I l l I I E l l i i 3 8V l MEDE OUT LT1528600 c O I I 3 1 i sh al C201 5 Y INPUT o z 1 t 4 poe EA tenuF AGHIMT 1 ond d C203 L202 Acta acne Aen Rana per rur tn 1 47 i Enn brad 1 d En 5 E i El CONT E AT aga 1 BM sto 1 i i HID BAD END i Aeos i san i d 1 0603 f l I I I it E
37. ct to consider designing an application based on TELIT module with internal antenna and or without a proper shielded box Some of these conditions may occur Antenna picks up digital noise coming from SIM card lines Antenna radiated field may interfere digital lines Digital lines in particular clock may radiate spurious in the surrounding space To overcome all these potential problems connection lines must be kept as short as possible and shielded SIM holder position has to be as far as possible from antenna RF bypass capacitors 10pF 33pF closed to SIM card SIM holder are another good care When connection is not short insertion of 10 1000hm resistor with 10 33pF capacitor RC filter is a good caution to improve EMI from SIMCLK line Do not insert resistor on SIMVCC SIMRST and SIMIO lines their use is not supported by SIM electrical interface A g 4 Reproduction forbidden without Telit Communications S p A written authorization All Right reserved page 52 of 73 PA e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 10 3ESD Take standard ESD caution if application based on TELIT module has SIM holder with contacts reachable from human body 10 4SIM Supply Do not connect capacitance greater than 10nF to SIMVCC line Other notes SIMIN doesn t require any pull up resistor It is built in SIM card is detected inserted when this line is short to ground If in the applicati
38. d page 35 of 73 Z e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 O TIP environment consideration For hands free car kit microphone you must take into account the voice attenuation due to the distance between the microphone itself and the talker when designing the external microphone amplifier Not only you must consider that the microphone will pick up also ambient noise to overcome this problem it is preferable to set the gain of the microphone 10dB lower with respect to the calculated value for a nominal sensitivity The corresponding reduction in signal level will be compensated by an increased voice volume of the talker which will speak louder because of the ambient noise For a car cabin usually the distance between the microphone itself and the talker is 40 50cm in these conditions the attenuation can be considered as a thumb rule around 20aB For the earphone we shall distinguish two different types the earphones having the microphone sustained close to the mouth and the ones having the microphone on the earpiece cable The same considerations for the additional voice attenuation due to the distance from the microphone and the noise pick up can be made for the earphone having the microphone on the earpiece cable while the other kind of earphone shall be threaten as an handset y TIP how to compensate the losses in car cabin hands free condition The voice signal that in the normal s
39. dio 14 MIC HF Al Handsfree microphone input phase nominal level 3mVrms Audio 15 MIC MTt Al Handset microphone signal input phase nominal level 50mVrms Audio 16 MIC MT Al Handset microphone signal input phase nominal level 50mVrms Audio SIM Card Interface 18 SIMVCC External SIM signal Power supply for the SIM 1 8 3V 19 SIMRST O External SIM signal Reset 1 8 3V 20 SIMIO I O External SIM signal Data I O 1 8 3V 21 SIMIN External SIM signal Presence active low A7KQ 1 8 3V 22 SIMCLK O External SIM signal Clock 1 8 3V Trace On this line a maximum of 10nF bypass capacitor is allowed E Reproduction forbidden without Telit Communications S p A written authorization All Right reserved page 9 of 73 Z e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 Internal Pin Signal I O Function Pull up Type 23 RX_TRACE RX Data for debug monitor CMOS 2 8V 24 TX TRACE O TX Data for debug monitor CMOS 2 8V Prog Data Hw Flow Control 25 C103 TXD Serial data input TXD from DTE CMOS 2 8V 26 C104 RXD O Serial data output to DTE CMOS 2 8V 27 C107 DSR O Output for Data set ready signal DSR to DTE CMOS 2 8V 28 C106 CTS O Output for Clear to send signal CTS to DTE CMOS 2 8V 29 C108 DTR Input for Data terminal ready signal DTR from DTE CMOS 2 8V 30 C125 RING O Output for Ring indicator signal RI to DTE CMOS 2 8V 31 C105 RTS Input for Request to send signal RTS from DTE CMOS 2 8V
40. e 3500Hz in order to have 1dB at 3kHz The cutoff frequency is given by the formula 1 1 freq _____ Hz 2x R6044C637 27 R606 C636 TIP example of calculation Let s assume you have a microphone with a sensitivity of 45 dBV my Pa and you want to use it in 1st differential microphone path Mic MT inputs in normal spoken conditions at acoustic pressure of 4 7dBPa As reported at page 33 the electrical level output from the microphone will be MicLevel 45 4 7 49 7 dByms corresponding to MicVoltage 10 1 721239410 Ving When the talker is screaming we will have a signal of 330 mV 4 on the Mic MT inputs due to a 20dB higher Mic Level see TIP 1 with a buffer gain Ga Ga 20 log AmplifierOutput MicVoltage 20 log 330 10 33 107 20 log 10 20dB The corresponding values for the resistors on the buffer could be if we keep the input resistance 10kQ R604 R606 gain R607 gain R605 10 15 150 kQ The commercial values of 150k0 8 15kQ are then chosen As a consequence the values of the capacitors C636 and C637 shall be C636 C637 1 21r 4000 R606 265 10 F A commercial value of 270pF gives a cutoff frequency of 3931Hz with an errorless than 1 896 Reproduction forbidden without Telit Communications S p A written authorization All Right reserved page 42 of 73 Z e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 8 5 2
41. e could be calculated with the following formula Integrated output voltage 2 value 1023 DAC OUT line must be integrated for example with a low band pass filter in order to obtain an analog voltage 12 1 2 Enabling DAC An AT command is available to use the DAC function The command is AT DAC lt enable gt lt value gt value scale factor of the integrated output voltage 0 1023 10 bit precision it must be present if lt enable gt 1 Refer to SW user guide or to GC864 QUAD PY AT commands specification for the full description of this function NOTE The DAC frequency is selected internally D A converter must not be used during POWERSAVING page 59 of 73 Z e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 12 1 3 Low Pass Filter Example R1 R2 R3 P1 G amp AAA AAN P3 12k 12k 12k INPUT dac out OUTPUT C1 100nF C2 100nF C3 100nF P2 a 8 P4 GND GND GND GND V GND page 60 of 73 PA e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 12 2ADC Converter 12 2 1 Description The on board A D are 11 bit converter They are able to read a voltage level in the range of 0 2 volts applied on the ADC pin input store and convert it into 11 bit word Min Max Units Input Voltage range 0 2 Volt AD conversion 11 bits Resolution lt 1 mV The GC864 QUAD PY module provides 3 Analog to Digital Converters The input lines are
42. esossossesossossesossossesoosossossossesosssssesse 72 16 Document Change Log rc AAAAAA 73 Reproduction forbidden without Telit Communications S p A written authorization All Right reserved page 5 of 73 PA e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 DISCLAIMER The information contained in this document is proprietary information of Telit Communications S p A Telit Communications S p A makes every effort to ensure the quality of the information it makes available Notwithstanding the foregoing Telit Communications S p A does not make any warranty as to the information contained herein and does not accept any liability for any injury loss or damage of any kind incurred by use of or reliance upon the information Telit Communications S p A disclaims any and all responsibility for the application of the devices characterized in this document and notes that the application of the device must comply with the safety standards of the applicable country and where applicable with the relevant wiring rules Telit Communications S p A reserves the right to make modifications additions and deletions to this document at any time and without notice 2006 Telit Communications S p A pF Reproduction forbidden without Telit Communications S p A written authorization All Right reserved page 6 of 73 PA e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07
43. g the voltage across the battery terminals rises when it reaches the fast charge threshold level the charging process goes into fast charge phase During the fast charge phase the process proceeds with a current limited charging this current limit depends on the required time for the complete charge and from the battery pack capacity During this phase the voltage across the battery terminals still raises but at a lower rate Once the battery voltage reaches its maximum voltage then the process goes into its third state Final charging The voltage measure to change the process status into final charge is very important It must be ensured that the maximum battery voltage is never exceeded otherwise the battery may be damaged and even explode Moreover for the constant voltage final chargers the constant voltage phase final charge must not start before the battery voltage has reached its maximum value otherwise the battery capacity will be highly reduced The final charge can be of two different types constant voltage or pulsed GC864 QUAD PY uses constant voltage The constant voltage charge proceeds with a fixed voltage regulator very accurately set to the maximum battery voltage and hence the current will decrease while the battery is becoming charged When the charging current falls below a certain fraction of the fast charge current value then the battery is considered fully charged the final charge stops and eventually starts the mainte
44. h these current peaks without big voltage drops this means that both the electrical design and the board layout must be designed for this current flow If the layout of the PCB is not well designed a strong noise floor is generated on the ground and the supply this will reflect on all the audio paths producing an audible annoying noise at 216 Hz if the voltage drop during the peak current absorption is too much then the device may even shutdown as a consequence of the supply voltage drop TIP The electrical design for the Power supply should be made ensuring it will be capable of a peak current output of atleast 2 A Se z Reproduction forbidden without Telit Communications S p A written authorization All Right CJ page of 73 Z e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 5 2 General Design Rules The principal guidelines for the Power Supply Design embrace three different design steps the electrical design the thermal design the PCB layout 5 2 1 Electrical Design Guidelines The electrical design of the power supply depends strongly from the power source where this power is drained We will distinguish them into three categories e 5Vinput typically PC internal regulator output e 12V input typically automotive e Battery 5 2 1 1 5V input Source Power Supply Design Guidelines e The desired output for the power supply is 3 8V hence there s not a big difference
45. hout Telit Communications S p A written authorization All Right reserved page 19 of 73 Z e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 An example of switching regulator with 12V input is 12Y input switching regulator 2 A 500 99 4 44 t124 INPUT Tre n C2059 L202 80202 E AA 4 3 8V OUTPUT Boost 8 pi D03316 t 1 pi pi 5 lan w53 B caio i00uF E f suour sense 2 aN ceo 0206 i i 0303 Chi Nba aen sour BE kaan bi 5TPE4402 GONT D R203 PF x7n END 2 c208 ark 2 76 GNE Baza ES 3v a LAE 500124 0603 CONT E d E ma EBD 0603 177 R204 4 FR 5 CAD BNO 5 2 1 3 Battery Source Power Supply Design Guidelines e The desired nominal output for the power supply is 3 8V and the maximum voltage allowed is 4 2V hence a single 3 7V Li lon cell battery type is suited for supplying the power to the Telit GC864 QUAD PY module The three cells Ni Cd or Ni MH 3 6 V Nom battery types or 4V PB types MUST NOT BE USED DIRECTLY since their maximum voltage can rise over the absolute maximum voltage for the GC864 QUAD PY and damage it NOTE DON T USE any Ni Cd Ni MH and Pb battery types directly connected with GC864 QUAD PY Their use can lead to overvoltage on the GC864 QUAD PY and damage it USE ONLY Li lon battery types A Bypass low ESR capacitor of adequate capacity must be provided i
46. ickness 3 2 mm 2 30 05 poros m CLEARANCE FOR CLOSE COMPONENTS 11 80 15 N MOVABLE RF CABLE A A P m HH p TES E Ol 36 2 0 3 33 140 15 1 2 3340 15 5 I e 5 i i 1 Y O re fa SR TO 3040 2 ES 0 8720 P 32 8k0 3 250 1 Reproduction forbidden without Telit Communications S p A written authorization All Right AA page 8 of 73 Z e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 3 GC864 module connections 3 1 PIN OUT The GC864 uses a 80 pin Molex p n 53949 0878 male connector for the connections with the external applications This connector matches the 54150 0878 model Internal Pin Signal I O Function Pull up Type Power Supply 1 VBATT Main power supply Power 2 VBATT Main power supply Power 3 VBATT Main power supply Power 4 VBATT Main power supply Power 5 GND Ground Power 6 GND Ground Power 7 GND Ground Power Audio 8 AXE Handsfree switching 100KQ CMOS 2 8V 9 EAR HFt AO Handsfree ear output phase Audio 10 EAR HF AO Handsfree ear output phase Audio 11 EAR MT AO Handset earphone signal output phase Audio 12 EAR MT AO Handset earphone signal output phase Audio 13 MIC HFt Al Handsfree microphone input phase nominal level 3mVrms Au
47. itions the voice will produce an acoustic pressure of 4 7dBPa 1kHz on the microphone membrane y TIP electrical equivalent signal and operating voice levels At normal spoken conditions a microphone having the suggested nominal sensitivity of 45dB Vmy Pa will produce the electrical equivalent signal MicLevel 45 4 7 49 7 ABy ms that means s MicVoltage 10 97 3 3 10 Vins During a call this level varies according to the volume of the talker voice usually the following rough thumb rule for the dynamic range may be used 1 the talker is screaming This is the strongest voice level condition the signal increases by 20dB 2 the talker is whispering This is the lowest voice level condition the voice level decreases by 50dB These changes must be considered for designing the external microphone amplifier y TIP example of external microphone amplifier calculation Let s suppose to use the 1 differential microphone path In this case the maximum differential input voltage to Mic MT lines is 365mMVms 1 03V pp corresponding to 8 76dBV Now we can calculate the maximum voltage gain of an external microphone amplifier G4 MicLevel 204B G 8 76dBV 49 7 20 G 8 76 40 9 20 G w youcan set Gaz 20dB to use standard resistor values z Reproduction forbidden without Telit Communications S p A written authorization All Right reserve
48. l refineries etc It is responsibility of the user to enforce the country regulation and the specific environment regulation Do not disassemble the product any mark of tampering will compromise the warranty validity We recommend following the instructions of the hardware user guides for a correct wiring of the product The product has to be supplied with a stabilized voltage source and the wiring has to be conforming to the security and fire prevention regulations The product has to be handled with care avoiding any contact with the pins because electrostatic discharges may damage the product itself Same cautions have to be taken for the SIM checking carefully the instruction for its use Do not insert or remove the SIM when the product is in power saving mode The system integrator is responsible of the functioning of the final product therefore care has to be taken to the external components of the module as well as of any project or installation issue because the risk of disturbing the GSM network or external devices or having impact on the security Should there be any doubt please refer to the technical documentation and the regulations in force Every module has to be equipped with a proper antenna with specific characteristics The antenna has to be installed with care in order to avoid any interference with other electronic devices and has to guarantee a minimum distance from the body 20 cm In case of this requirement canno
49. le and OEM hardware Several configurations can be designed for the serial port on the OEM hardware but the most common are RS232 PC com port microcontroller UART 2 8V 3V Universal Asynchronous Receive Transmit microcontroller UART 5V or other voltages different from 2 8V Depending from the type of serial port on the OEM hardware a level translator circuit may be needed to make the system work The only configuration that doesn t need a level translation is the 2 8V UART The serial port on the GC864 is a 2 8V UART with all the 7 RS232 signals It differs from the PC RS232 in the signal polarity RS232 is reversed and levels The levels for the GC864 UART are the CMOS levels Absolute EN D MES Not Functional Parameter parameter level on any LM 3V Mex 75V digital pad when on Input voltage on 0 3V 3 0 V analog pads when on Operating Range Interface levels 2 8V CMOS Level Mo Max Input low level Vi 0 5V Ouput gh Tevel Vor Output low level VoL 0 35V sx eos Reproduction forbidden without Telit Communications S p A written authorization All Right reserved page 26 of 73 Z e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 The signals of the GC864 serial port are GC864 pin Number 1 DCD 32 Data Carrier Detect Output from the GC864 that indicates the dcd uart carrier presence tx uart rx uart 4 DTR 29 Data Terminal Ready Input to the GC864 tha
50. lit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 13 1 2 EVB for Transchip camera support In order to interface the Telit GC864 QUAD PY with a CMOS camera Telit has developed an evaluation board The EVK allows the connector of all Telit modules through 2 connectors of 40 pins each The I2CBUS DUAL CAMERA board is plugged in the 2 connectors of 30 pins each on the module board CAMERA BOARD MODULE BOARD MAIN BOARD pom page 65 of 73 gr Reproduction forbidden without Telit Communications S p A written authorization All Right reserved PA e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 13 1 3 Block Diagram for supported cameras The numbers on the left side of the Camera s connectors refers to Module Connector s pin number DVDD is VAUX1 power supply from GC864 QUAD PY CAMERA TRANSCHIP PD 6 1 GND 2 AVDD 3 PD 4 CAM CIK 5 GND 6 7 8 9 10 4 42 13 14 15 16 17 18 DVDD 19 IICSDA CAM 20 DVDD AVDD GND 21 PD 22 GND 23 24 S DVDD MON1_CAM CAM_CLK 5 y li d sg E Reproduction forbidden without Telit Communications S p A written authorization All Right reserved page 66 of 73
51. luded The GC864 QUAD PY module is conform with the following US Directives e Use of RF Spectrum Standards FCC 47 Part 24 GSM 1900 e EMC Electromagnetic Compatibility Standards FCC47 Part 15 To meet the FCC s RF exposure rules and regulations The system antenna s used for this transmitter must be installed to provide a separation distance of at least 20 cm from all the persons and must not be co located or operating in conjunction with any other antenna or transmitter The system antenna s used for this module must not exceed 3 dBi for mobile and fixed or mobile operating configurations Users and installers must be provided with antenna installation instructions and transmitter operating conditions for satisfying RF exposure compliance Manufacturers of mobile fixed or portable devices incorporating this module are advised to clarify any regulatory questions and to have their complete product tested and approved for FCC compliance page 71 of 73 Z e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 15 SAFETY RECOMMANDATIONS READ CAREFULLY Be sure the use of this product is allowed in the country and in the environment required The use of this product may be dangerous and has to be avoided in the following areas U Where it can interfere with other electronic devices in environments such as hospitals airports aircrafts etc Q Where there is risk of explosion such as gasoline stations oi
52. n order to cut the current absorption peaks a 100 F tantalum capacitor is usually suited Make sure the low ESR capacitor usually a tantalum one is rated at least 10V A protection diode should be inserted close to the power input in order to save the GC864 QUAD PY from power polarity inversion Otherwise the battery connector should be done in a way to avoid polarity inversions when connecting the battery The battery capacity must be at least 500mAh in order to withstand the current peaks of 2A the suggested capacity is from 500mAh to 1000mAh Se d Reproduction forbidden without Telit Communications S p A written authorization All Right CJ page of 73 Z e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 5 2 1 4 Battery Charge control Circuitry Design Guidelines The charging process for Li lon Batteries can be divided into 4 phases e Qualification and trickle charging e Fast charge 1 constant current e Final charge constant voltage or pulsed charging e Maintenance charge The qualification process consists in a battery voltage measure indicating roughly its charge status If the battery is deeply discharged that means its voltage is lower than the trickle charging threshold then the charge must start slowly possibly with a current limited pre charging process where the current is kept very low with respect to the fast charge value the trickle charging During the trickle chargin
53. n the echo canceller characteristics of the GC864 QUAD PY internal audio path from the external audio path Example of car kit amplifier schematic HIGH POWER EXT EAR AMPLIFIER 6w o iS eL ecc O xml a e a e e AA ta E in ver a E 5 EE i i Aso 4 m E4P HF4 1 T RS x 0913 Agog TO SPEAKER lt The __ te Bn 18k 1 Li L a B OHM i Tht RO Lu al 3 ms me in F i lt ERSTES z JEAP H pa MODE c902 caos Big 1 none onour 5 i in VA mn any T PLOGd i i E f C940 C308 i d o 50 el AUTE CONTROLLED x uM ile ALWAYS DN GONT E moa 77 END ND eun AMPLI POWER CONTROL z Reproduction forbidden without Telit Communications S p A written authorization All Right reserved page 51 of 73 Z e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 10 SIM DESIGN GUIDES In all Telit modules there are five pins for SIM card holder connection These lines are SIMVCC SIM Power supply SIMRST SIM Reset SIMIO SIM Data SIMIN SIM Presence Absence SIMCLK SIM Clock SIM connection must take in account of four key issues 10 1 Data Integrity Standard rules for digital layout and routing must be followed taking in consideration that SIMCLK has frequency of 3 57 MHz and SIMIO has 9600Bps baud rate 10 2EMI EMC This is a key aspe
54. nance The pulsed charge process has no voltage regulation instead the charge continues with pulses Usually the pulse charge works in the following manner the charge is stopped for some time let s say few hundreds of ms then the battery voltage will be measured and when it drops below its maximum value a fixed time length charging pulse is issued As the battery approaches its full charge the off time will become longer hence the duty cycle of the pulses will decrease The battery is considered fully charged when the pulse duty cycle is less than a threshold value typically 1096 the pulse charge stops and eventually the maintenance starts The last phase is not properly a charging phase since the battery at this point is fully charged and the process may stop after the final charge The maintenance charge provides an additional charging process to compensate for the charge leak typical of a Li lon battery It is done by issuing pulses with a fixed time length again few hundreds of ms and a duty cycle around 5 or less This last phase is not implemented in the GC864 QUAD PY internal charging algorithm so that the battery once charged is left discharging down to a certain threshold so that it is cycled from full charge to slight discharge even if the battery charger is always inserted This guarantees that anyway the remaining charge in the battery is a good percentage and that the battery is not damaged by keeping it always fully charged Li l
55. ning half of overall gain to each amplifier you will obtain the requested gain because of doubling the microphone signal path in fact by the use of two amplifiers the upper as inverting and the lower as not inverting configuration we obtain an additional 6dB gain 2 times Remember the not inverting amplifier section gain shall not be less than 1 Like for the balanced buffered microphone the amplifier overall gain can be modify changing the value of resistor R719 R720 and R711 and as a consequence the capacitors C726 and C727 It is advisable to change R708 only if you have difficulty to find a commercial value for R711 in this case change R708 as little as possible The 3dB bandwidth is given by the approximated formula considering C725 gt gt C726 143 C eos Reproduction forbidden without Telit Communications S p A written authorization All Right reserved page 43 of 73 Z e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 Hz 1 1 27 R719 C726 2x R711 C727 freq The buffer bandwidth at 3dB shall be 4KHz Note that the biasing of the operational amplifier is given for the inverting amplifier by the series divider R714 R715 The 100nF capacitor C719 is needed to filter the noise that could be coupled to that divider For the not inverting operational amplifier the biasing is given by a different divider R715 R717 with the capacitor C720 and through a series resistor
56. ns e Average current consumption during transmission PWR level max rms 500mA e Average current consumption during transmission Y PWR level min rms 100mA e Average current during Power Saving 4mA e Average current during idle Power Saving disabled 19mA O NOTE The average consumption during transmissions depends on the power level at which the device is requested to transmit by the network The average current consumption hence varies significantly Considering the very low current during idle especially if Power Saving function is enabled it is possible to consider from the thermal point of view that the device absorbs current significantly only during calls If we assume that the device stays into transmission for short periods of time let s say few minutes and then remains for a quite long time in idle let s say one hour then the power supply has always the time to cool down between the calls and the heat sink could be smaller than the calculated one for 500mA maximum RMS current or even could be the simple chip package no heat sink Moreover in the average network conditions the device is requested to transmit at a lower power level than the maximum and hence the current consumption will be less than the 500mA being usually around 150mA For these reasons the thermal design is rarely a concern and the simple ground plane where the power supply chip is placed can be enough to ensure a good thermal condition and avoid
57. o three different categories e handset earphone low power typically a handset e hands free earphone low power typically a earphone e car kit speakerphone high power typically a speaker The three groups have different power requirements usually the first two applications need only few mW of power which can be directly drained from the GC864 QUAD PY pads provided a suited speaker is used This direct connect design is the cheaper and simpler solution and will be suited for the most of the earphone design requirements There s no need to decouple the output ear lines if a suited earpiece is connected For the last group the speakerphone a power amplifier is required to raise the output power up to 5 10W required in a car cabin application All the designs shall comply with the following guidelines e Where possible use a bridged earphone circuitry to achieve the maximum power output from the device e Keep the earphone traces on the PCB and wires as short as possible e f your application requires a single ended earpiece and you want a direct connection then leave one of the two output lines open and use only the other referred to ground Remember that in this case the power output is 4 times lower than the bridged circuit and may not be enough to ensure a good voice volume e Make sure that the earphone traces in the PCB don t cross or run parallel to noisy traces especially the power line e The cable to the speaker shall be
58. on rechargeable battery usually deteriorate when kept fully charged i 49 Reproduction forbidden without Telit Communications S p A written authorization All Right reserved page 21 of 73 Z e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 Last but not least in some applications it is highly desired that the charging process restarts when the battery is discharged and its voltage drops below a certain threshold GC864 QUAD PY internal charger does it As you can see the charging process is not a trivial task to be done moreover all these operations should start only if battery temperature is inside a charging range usually 5 C 45 C The GC864 QUAD PY measures the temperature of its internal component in order to satisfy this last requirement it s not exactly the same as the battery temperature but in common application the two temperature should not differ too much and the charging temperature range should be guaranteed NOTE For all the threshold voltages inside the GC864 QUAD PY all threshold are fixed in order to maximize Li lon o battery performances and do not need to be changed NOTE In this application the battery charger input current must be limited to less than 400mA This can be done by O using a current limited wall adapter as the power source 5 2 2 Thermal Design Guidelines The thermal design for the power supply heat sink should be done with the following specificatio
59. on the SIM holder doesn t foresee the switch for the presence absence of the SIM card the SIMIN line must be connected to ground 10 5SCHEMATIC 0201 FMS006Z 2001 0 SIMIO SIMCLK SIMRST SIMVCC SIMIN SIMCLK Reproduction forbidden without Telit Communications S p A written authorization All Right reserved page 53 of 73 Z e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 10 6LAYOUT Revraduci n forbidden without Telit Communications S p A written authorization All Right Ad page 54 of 73 PA e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 11 General Purpose I O The general purpose l O pads can be configured to act in three different ways input output alternate function internally controlled Input pads can only be read and report the digital value high or low present on the pad at the read time output pads can only be written or queried and set the value of the pad output an alternate function pad is internally controlled by the GC864 QUAD PY firmware and acts depending on the function implemented Not all GPIO pads support all these three modes GPIO5 supports all three modes and can be input output RFTX monitor output Alternate function GPIO6 supports all three modes and can be input output alarm output Alternate function GPIO7 supports all three modes and can be input output buzzer
60. onnector to the power regulator IC must be wide enough to ensure no voltage drops occur when the 2A current peaks are absorbed Note that this is not made in order to save power loss but especially to avoid the voltage drops on the power line at the current peaks frequency of 216 Hz that will reflect on all the components connected to that supply introducing the noise floor at the burst base frequency For this reason while a voltage drop of 300 400 mV may be acceptable from the power loss point of view the same voltage drop may not be acceptable from the noise point of view If your application doesn t have audio interface but only uses the data feature of the Telit GC864 QUAD PY then this noise is not so disturbing and power supply layout design can be more forgiving e The PCB traces to the GC864 QUAD PY and the Bypass capacitor must be wide enough to ensure no significant voltage drops occur when the 2A current peaks are absorbed This is for the same reason as previous point Try to keep this trace as short as possible e The PCB traces connecting the Switching output to the inductor and the switching diode must be kept as short as possible by placing the inductor and the diode very close to the power switching IC only for switching power supply This is done in order to reduce the radiated field noise at the switching frequency 100 500 kHz usually e The use of a good common ground plane is suggested e The placement of the power suppl
61. onsregeln erfolgen SL integracija GSM GPRS GC864 QUAD modula v uporabni ki aplikaciji bo morala upo tevati projektna navodila opisana v tem priro niku SP La utilizaci n del modulo GSM GPRS GC864 QUAD debe ser conforme a los usos para los cuales ha sido dise ado descritos en este manual del usuario FR L int gration du module cellulaire GC864 QUAD GSM GPRS dans l application de l utilisateur sera faite selon les r gles de conception d crites dans ce manuel HE 22 07 raa Sw DX WUPNA HANA MI 20022 MUNA nvnim ns nu WIND m wncrWa nn ny GC864 QUAD The information presented in this document is believed to be accurate and reliable However no responsibility is assumed by Telit Communication S p A for its use nor any infringement of patents or other rights of third parties which may result from its use No license is granted by implication or otherwise under any patent rights of Telit Communication S p A other than for circuitry embodied in Telit products This document is subject to change without notice y Reproduction forbidden without Telit Communications S p A written authorization All Right reserved page 7 of 73 Z e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 2 GC864 Mechanical Dimensions The Telit GC864 module overall dimensions are e Length 36 2 mm e Width 30 mm e Th
62. output Alternate function As Reproduction forbidden without Telit Communications S p A written authorization All Right reserved page 55 of 73 4 e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 11 1Logic level specifications Where not specifically stated all the interface circuits work at 2 8V CMOS logic levels The following table shows the logic level specifications used in the GC864 and GC864 interface circuits Absolute Maximum Ratings Not Functional Parameter Min Max Input level on any 0 3V 3 75V digital pin when on Input voltage on 0 3V 3 0 V analog pins when on Operating Range Interface levels 2 8V CMOS Level Min Max Input high level 2 1V 3 3V Input low level OV 0 5V Output high level 2 2V 3 0V Output low level OV 0 35V For 2 0V signals Operating Range Interface levels 2 0V CMOS Level Min Max Input high level 1 6V 3 3V Input low level OV 0 4V Output high level 1 65V 2 2V Output low level OV 0 35V E Reproduction forbidden without Telit Communications S p A written authorization All Right reserved page 56 of 73 Z e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 11 2 Using a GPIO Pad as INPUT The GPIO pads when used as inputs can be connected to a digital output of another device and report its status provided this device has interface levels compatible with the 2 8V CMOS levels of the GPIO If the digital output of the device
63. owing for a lower voltage multiplying ratio on the level translator Note that the negative signal voltage must be less than OV and hence some sort of level translation is always required The simplest way to translate the levels and invert the signal is by using a single chip level translator There are a multitude of them differing in the number of driver and receiver and in the levels be sure to get a true RS232 level translator not a RS485 or other standards By convention the driver is the level translator from the 0 3V UART level to the RS232 level while the receiver is the translator from RS232 level to 0 3V UART In order to translate the whole set of control lines of the UART you will need 5 driver 3 receiver NOTE The digital input lines working at 2 8VCMOS have an absolute maximum input voltage of 3 75V therefore the level translator IC shall not be powered by the 3 8V supply of the module Instead it shall be powered from a 2 8V 3 0V dedicated power supply This is because in this way the level translator IC outputs on the module side i e GC864 inputs will work at 3 8V interface levels stressing the module inputs at its maximum input voltage This can be acceptable for evaluation purposes but not on production devices NOTE In order to be able to do in circuit reprogramming of the GC864 firmware the serial port on the Telit GC864 shall be available for translation into RS232 and either it s controlling
64. poken conditions produces on the microphone membrane an acoustic pressure of 4 7dBPa at 1kHz will have a further attenuation of 20dB due the 50cm distance Therefore a microphone having the suggested nominal sensitivity of 45dBV y Pa will produce a lower electrical that means MicVollage s 19 777 0 33 40 Setting the microphone gain at 10dB 3 times the signal in the nominal conditions on the Mic HF inputs s of GC864 QUAD PY Telit Module will be Mic HF Level 0 33 10 3 1 10 a l l S ll Hence in these conditions the signal level on the Mic HF input pads of the GC864 QUAD PY is 10 dB 3 times lower than the nominal as suggested KE B EU Reproduction forbidden without Telit Communications S p A written authorization All Right page 36 of 73 Z e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 8 2 General Design Rules There are several configurations for the audio paths but the most effective difference is between balanced and unbalanced microphone configuration It is highly recommended to keep the whole microphone path balanced even if this means having 2 wires connecting the microphone instead of one needed plus ground in the unbalanced case The balanced circuitry is more suited because of its good common mode noise rejection reducing the 216 Hz burst noise produced during the GSM transmissions e Where possible use balanced mic
65. rnal 47KQ pull up resistor either the DTR dtr uart and RTS rts uart input lines are not pulled up internally so an external pull up resistor of 47KQ may be required 7 3 VAUX power output A regulated power supply output is provided in order to supply small devices from module This output is active when the module is ON and goes off when module is shut down The operating range characteristics of the supply are Operating Range Vout power supply Min Typ Max Output voltage 2 75V 2 85V 2 95V Output current 100mA Output bypass capacitor 2 2UF Pull up resistors can be connected to the VAUX pad provided that the pulled up lines are GC 864 input lines connected to open collector outputs in order to avoid latch up problems on the GC864 Care must be taken to avoid latch up on the GC864 and the use of this output line to power electronic devices shall be considered with care especially for devices that generate spikes and noise such as level translators digital ICs or microcontroller failure in any of these condition can severely compromise the GC864 functionality NOTE The input lines working at 2 8VCMOS can be pulled up with 47KO resistors that can be connected directly to the VAUX line NO disturbing devices should be powered with the VAUX line otherwise the module functionality may be compromised page 31 of 73 Z e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 8 Audio Section Overview The
66. rophone circuitry e Keep the microphone traces on the PCB and wires as short as possible e f your application requires an unbalanced microphone then keep the lines on the PCB balanced and unbalance the path close to the microphone wire connector if possible e For the microphone biasing voltage use a dedicated voltage regulator and a capacitor multiply circuit e Make sure that the microphone traces in the PCB don t cross or run parallel to noisy traces especially the power line e f possible put all around to the microphone lines a ground trace connected to the ground plane by several vias This is done in order to simulate a shielded trace on the PCB e The biasing circuit and eventually the buffer can be designed in the same manner for the internal and external microphones 8 3 Other considerations If your application is a hands free car kit scenario but you need to put microphone and speaker inside the same box e try to have the maximum possible distance between them at least 7cm e becauses the microphone type is very important if you use an omni directional one and this is the typical applicaton please seal it on the rear side no back cavity in order not to collect unwanted signals e try to make divergent the main axes of the two devices Reproduction forbidden without Telit Communications S p A written authorization All Right reserved page 37 of 73 Z e Telit GC864 Hardware User Guide 1
67. t be satisfied the system integrator has to assess the final product against the SAR regulation The European Community provides some Directives for the electronic equipments introduced on the market All the relevant information s are available on the European Community website http europa eu int comm enterprise rtte dir99 5 htm The text of the Directive 99 05 regarding telecommunication equipments is available while the applicable Directives Low Voltage and EMC are available at http europa eu int comm enterprise electr equipment index en htm page 72 of 73 Z e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 16 Document Change Log Revision Date Changes ISSUE ZO 12 06 06 Release First ISSUE 0 ISSUE 1 07 09 06 Full Review of the manual Added ADC description Added DAC description Added Pinout and Process flow description Added Packaging Reproduction forbidden without Telit Communications S p A written authorization All Right reserved page 73 of 73
68. t controls the DTE dtr uart READY condition ground ela ll LL A dsr uart module is ready rts uart Hardware flow control KPA sev ore cts uart Hardware flow control pL Led Output from the GC864 that indicates the ri uart incoming call condition NOTE According to V 24 RX TX signal names are referred to the application side therefore on the GC864 side these signal are on the opposite direction TXD on the application side will be connected to the receive line here named TXD rx uart of the GC864 serial port and viceversa for RX TIP For a minimum implementation only the TXD and RXD lines can be connected the other y lines can be left open provided a software flow control is implemented The signals in the UART connector on the EVK2 are DCD RXD TXD DTR GND DSR RTS CTS RI GND z Reproduction forbidden without Telit Communications S p A written authorization All Right reserved page 27 of 73 PA e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 7 1 RS232 level translation In order to interface the Telit GC864 with a PC com port or a RS232 EIA TIA 232 application a level translator is required This level translator must invert the electrical signal in both directions change the level from 0 3V to 15 15V Actually the RS232 UART 16450 16550 16650 16750 chipsets accept signals with lower levels on the RS232 side EIA TIA 562 all
69. the resistors R2 and R3 must have the same value to keep the circuit balanced NOTE The cable to the microphone should not be shielded instead a twisted pair cable shall be used NOTE The microphone sensitivity changes with the value of R2 and R3 Usually the microphones are characterized with 2kO biasing resistance so try to keep the sum of R2 and R3 around 2kQ Refer to your microphone manufacturer for the mic characteristics 8 4 2 Unbalanced Microphone Biasing The unbalanced microphone biasing voltage should be obtained from a dedicated voltage regulator in order to eliminate the noise present on the power lines This regulator can be the same for all the audio paths The microphone should be supplied from a capacitor multiply circuit For example a circuit for the unbalanced microphone biasing can be 4 3V MIC MIC Biasing Regulator Capacity multiply circuit aaa A II U1 LP29B041M5x 3 0 V 1N v OUT GND C1 P iouF ON OFF Nox ay LOZA CONTB KA Mads GNO AO Electret microphone Moc T n i 1 T T 1 A pa Snielded 1 To Mic Buffer amplifier Cable 5 Mit i i mc H H i P ca 2 220nF e 10v paaa a GND GNO ee eee Reproduction forbidden without Telit Communications S p A written authorization All Right reserved page 39 of 73 oo Z e Telit GC864 Hardware User Guide 1vv0300733 Rev
70. to be connected with the GPIO input pad has interface levels different from the 2 8V CMOS then it can be connected to GPIO1 or can be buffered with an open collector transistor provided a 47KO pull up resistor is connected as seen in the paragraph 7 2 5V UART level translation 11 3 Using a GPIO Pad as OUTPUT The GPIO pads when used as outputs can drive 2 8V CMOS digital devices or compatible hardware When set as outputs the pads have a push pull output and therefore the pull up resistor may be omitted 11 4Using the Alarm Output GPIO6 The GPIO6 pad when configured as Alarm Output is controlled by the GC864 QUAD PY module and will rise when the alarm starts and fall after the issue of a dedicated AT command This output can be used to power up the GC864 QUAD PY controlling microcontroller or application at the alarm time giving you the possibility to program a timely system wake up to achieve some periodic actions and completely turn off either the application and the GC864 QUAD PY during sleep periods drammatically reducing the sleep comsumption to few pA In battery powered devices this feature will greatly improve the autonomy of the device 11 5 Using the Buzzer Output GPIO7 The GPIO7 pad when configured as Buzzer Output is controlled by the GC864 QUAD PY module and will drive with appropriate square waves a Buzzer driver LE 5 L4 Reproduction forbidden without Telit Communications S p A written authoriz
71. udio path is suited for y Handset applications while the Mic_HF audio path is suited for hands free function car kit The Earphone applications should be made using the Mic HF audio path but DISABLING the echo canceller by software AT command If the echo canceller is left active with the Earphone then some echo might be introduced by the echo cancel algorithm Mic MT f differential microphone path e line coupling AC e line type balanced e coupling capacitor 2 100nF e differential input resistance 50kQ e differential input voltage S 1 03V 365mV 4 e microphone nominal sensitivity 45 dBVims Pa e analog gain suggested 20dB e echocanceller type handset Mic HF 2 differential microphone path e line coupling AC e line type balanced e coupling capacitor 2 100nF e differential input resistance 50kQ e differential input voltage S 65mV 23mV ms e microphone nominal sensitivity 45 dBVims Pa analog gain suggested echo canceller type 10dB car kit hands free page 34 of 73 Z e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 p TIP definition of the nominal sensitivity of the microphone lines The nominal sensitivity of the microphone lines indicates the voltage level on the GC864 QUAD PY pins present during normal spoken conditions For a handset the normal spoken conditions take place when the talker mouth is 7cm far from the microphone under these cond
72. vv0300733 Rev 1 07 09 06 8 4 Microphone Biasing The electret microphones usually need a biasing voltage to work properly Refer to your microphone provider for the characteristics required O NOTE The microphones have a hot wire were the positive biasing must be connected Usually it is indicated by a symbol or a red point If the polarity of the bias is reversed then the microphone will not work properly For this reason be sure to respect the mic biasing polarity 8 4 1 Balanced Microphone Biasing The balanced microphone bias voltage should be obtained from a dedicated voltage regulator in order to eliminate the noise present on the power lines This regulator can be the same for all the audio paths The microphone should be supplied from a capacitor multiply circuit For example a circuit for the balanced microphone biasing can be 3 By 3V MIC MIC Biasing Regulator Capacity multiply circuit Lu 1 t i i LI D r C1 i our l t ah i i i Li i i Li Wi H i GND L D i i A 4 l i Electret microphone 1 aalaga RS MICH C3 l i 1 r 1 H d i To MIC Buffer amplifier big a MIC CJ L e Reproduction forbidden without Telit Communications S p A written authorization All Right reserved page 38 of 73 Z e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 NOTE In the balanced application
73. y on the board should be done in such a way to guarantee that the high current return paths in the ground plane are not overlapped to any noise sensitive circuitry as the microphone amplifier buffer or earphone amplifier e The power supply input cables should be kept separate from noise sensitive lines such as microphone earphone cables page 23 of 73 Z e Telit GC864 Hardware User Guide 1vv0300733 Rev 1 07 09 06 6 Antenna The antenna connection and board layout design are the most important part in the full product design and they strongly reflect on the product overall performances hence read carefully and follow the requirements and the guidelines for a proper design 6 1 GSM Antenna Requirements As suggested on the Product Description the antenna for a Telit GC864 QUAD PY device shall fulfill the following requirements ANTENNA REQUIREMENTS Frequency range Standard Dual Band GSM DCS frequency range or Standard Quad Band GSM DCS PCS frequency range if used for all four bands Bandwidth 80 MHz in GSM amp 170 MHz in DCS amp 140 MHz PCS band Gain Gain 3dBi Impedance 50 ohm Input power gt 2 W peak power VSWR absolute lt 10 1 max VSWR lt 211 recommended Furthermore if the device is developed for the US market and or Canada market it shall comply to the FCC and or IC approval requirements This device is to be used only for mobile and fixed application The

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