EVBUM2328 - NCV7681AGEVB Evaluation Board User`s Manual
Contents
1. ours ours enD ours oure RSTOP our by RTAIL ours Pt R2 3 01K R3 1 62K cas OOOO GND GND GND GND DIAG RESET C1 100nF 29313 O led_diode led_diode led_diode OUT1 D19 D20 D21 29312 O led_diode led_diode led_diode OUT2 D16 D17 D18 29311 O led_diode led_diode led_diode OUT3 D13 D14 D15 29310 O led_diode led_diode led_diode outa D10 Dit D12 to 39 O led_diode led_diode led_diode OUTS D7 D8 D9 1o us O led_diode led_diode led_diode OUTS D4 D5 D6 1o 37 O led_diode led_diode led_diode ONE D1 D2 D3 1o J6 O led_diode led_diode led_diode OUTS Figure 6 Evaluation Board Schematic www onsemi com 5 NCV7681AGEVB BILL OF MATERIALS Table 4 NCV7681A LATCH OFF EVALUATION BOARD BILL OF MATERIALS Toler Manufacturer Substitution i EA 10 nF 0805 KEMET C0805C103K5RACTU EA 0 68 uF 0805 KEMET C0805C684K5RACTU ves O i ae oy i D25 D26 2 D27 Description LED Storage Capacitor Debounce Capacitor Input Capacitor Loop Stabilization Capacitor Steering Diode DIAG Reporting LED 0 22 uF 0805 KEMET C0805C224K5RACTU 24 Display LEDs led_diode G6SP OSRAM LRG6SP CADB 1 1 p ON SEMICONDUCTOR MRA4003T3G MRA4003 SMA_DIODE led_diode LITE ON INC LTST C171GKT J3 J14 J18 Dual Jumper Posts 100 mil spacing JUMPER 3M 961102 6404 AR J15 J17 Triple Jumper Posts 100 mil s2. BOARD OPERATING CONDITIONS T e a External Supply Voltage Vpat Oo o a y Junction Temperature NCV7681A Functional operation above the stresses listed in the Recommended Operating Ranges is not implied Extended exposure to stresses beyond the Recommended Operating Ranges limits may affect device reliability www onsemi com 3 NCV7681AGEVB Table 3 PIN FUNCTION DESCRIPTION Connector Pin Number Terminal Name Description Power J1 VBAT VBAT Power Supply Input Voltage 14 V J2 GND GND Ground J3 RSTOP Programmable DC Current J4 RTAIL Programmable Duty Cycle J5 DIAG DIAG Open Drain Output J6 OUT1 Current Outputs J7 OUT2 J8 OUT3 J9 OUT4 OUT5 OUT6 J12 OUT7 OUT8 BALLAST IN Connect when Using External Ballast Transistor Connects Drain of External Ballast Transistor to Vstrina J15 Connection to Top of the FB Resistor Network or Open Circuit J16 Connection to Short FB Pin to Ground or Open Circuit Connection for Ballast Drive Gate Pin to Ballast Gate or to Ground BALLAST OUT Connect when Not Using External Ballast Transistor Shorts S D of External Transistor User Interface Locations This lists all the user options available on the evaluation Figure 5 shows all the user interface locations board Figure 5 User Interface Locations Black STOP TAIL external connections Orange OUT1 OUTS8 output posts Grey STOP TAIL switches Yellow Ballast Tran
3. NCV7681AGEVB NCV7681AGEVB Evaluation Board User s Manual Eight 8 Channel Enhanced 100 mA Linear Current Regulator and Controller for Automotive LED Lighting Evaluation Board User s Manual Description The NCV7681A is an octal LED driver designed for automotive LED car rear combination lamps External programmability of the NCV7681A allows the user to set the tail current and stop currents using a single resistor for each function The NCV7681A does NOT have a one out all out function A one out all out function disables all strings when an open circuit occurs on one string Systems requiring one out all out have the option of using the NCV7681L The two typical control inputs into the system are available through on board switches or through the pin connections to external controls The two system control inputs are the STOP and TAIL functions The STOP function displays a 100 duty cycle current through the LEDs The TAIL function displays a programmable PWM current through the LEDs Features STOP TAIL 100 Duty Cycle PWM Modes Flexibility for External LED Connections LED Current Programmability RSTOP LED PWM Programmability RTAIL STOP TAIL External Connections External DIAG Pin Connection Application The NCV7681A features the ability to drive 8 individual strings of LEDs reference Figure 2 with a programmed current for a DC current for STOP mode and a PWM current for TAIL model The
4. bsidiaries affiliates and distributors harmless against all claims costs damages and expenses and reasonable attorney fees arising out of directly or indirectly any claim of personal injury or death associated with such unintended or unauthorized use even if such claim alleges that SCILLC was negligent regarding the design or manufacture of the part SCILLC is an Equal Opportunity Affirmative Action Employer This literature is subject to all applicable copyright laws and is not for resale in any manner PUBLICATION ORDERING INFORMATION LITERATURE FULFILLMENT N American Technical Support 800 282 9855 Toll Free ON Semiconductor Website www onsemi com Literature Distribution Center for ON Semiconductor USA Canada 19521 E 32nd Pkwy Aurora Colorado 80011 USA Europe Middle East and Africa Technical Support Order Literature http www onsemi com orderlit Phone 303 675 2175 or 800 344 3860 Toll Free USA Canada Phone 421 33 790 2910 chief ee Fax 303 675 2176 or 800 344 3867 Toll Free USA Canada Japan Customer Focus Center For additional information please contact your local Email orderlit onsemi com Phone 81 3 5817 1050 Sales Representative EVBUM2328 D
5. de secrets and other intellectual property A listing of SCILLC s product patent coverage may be accessed at www onsemi com site pdf Patent Marking pdf SCILLC reserves the right to make changes without further notice to any products herein SCILLC makes no warranty representation or guarantee regarding the suitability of its products for any particular purpose nor does SCILLC assume any liability arising out of the application or use of any product or circuit and specifically disclaims any and all liability including without limitation special consequential or incidental damages Typical parameters which may be provided in SCILLC data sheets and or specifications can and do vary in different applications and actual performance may vary over time All operating parameters including Typicals must be validated for each customer application by customer s technical experts SCILLC does not convey any license under its patent rights nor the rights of others SCILLC products are not designed intended or authorized for use as components in systems intended for surgical implant into the body or other applications intended to support or sustain life or for any other application in which the failure of the SCILLC product could create a situation where personal injury or death may occur Should Buyer purchase or use SCILLC products for any such unintended or unauthorized application Buyer shall indemnify and hold SCILLC and its officers employees su
6. pacing JUMPER 961102 6404 AR Jumper Banana Jack Banana Jack DIAG Illumination Transistor Switch Logic Resistors RSTOP Program Resistor RTAIL Program Resistor Vstring Program Resistor Gate source Resistor Vstring Program Resistor Current Setting Resistor 2N7002W a SOT23M4 10 kQ 0805 3 01 kQ 0805 1 62 kQ 0805 9 53 kQ 0805 0805 0805 BANANA BANANA 1 kQ 1 kQ SULLINS CONNECTOR SOLUTIONS NCH ECTIVITY UTIONS NCH ECTIVITY UTIONS ON SEMICONDUCTOR VISHAY DA LE VISHAY DALE VISHAY DALE VISHAY DALE VISHAY DALE LE VISHAY DA QPC02SXGN RC 108 0740 001 108 0740 001 ONC 2N7002WT1G BKN CRCW08051 0KOFKEA ves Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes haere Mell CRCW08054K99FKEA TP1 TP18 TAIL User Interface Switches SPST NO 0 05A 24V Tactile Switch NCV7681A SOIC 16WB epad iad i o NVD2955 MINITOGGLE 16WEPAD C amp K COMPONENTS TE Connectivity Alcoswitch KEYSTONE ELECTRONICS ON SEMICONDUCTOR www onsemi com 6 T101MH9CBE 1 1825910 0 DPAK3_SMD ON SEMICONDUCTOR NVD2955T4G NCV7681AGEVB ON Semiconductor and the W are registered trademarks of Semiconductor Components Industries LLC SCILLC or its subsidiaries in the United States and or other countries SCILLC owns the rights to a number of patents trademarks copyrights tra
7. pecific designs with external LEDs and programming of the current and duty cycle External control points are also provided in addition to the on board control switches The user must adhere to the absolute maximum ratings when using off board connections Note the inclusion of the Open Load Disable Threshold in the NCV7681A device This is included to avoid false open load detection at low supply voltages due to headroom issues with external LEDs Operation of LED drive current is valid above the Output Under Voltage Lockout threshold Vp 4 1 V typ allowing for illumination down to that voltage but open load detection is only valid above Vp 7 7 V typ An LED indicator with a current setting resistor provides illumination of these conditions Jumper J5 provides access to these pins for the user to use off board External LEDs The NCV7681AGEVB is compatible for use with external LEDs To use external LEDs 1 Remove J14 or J18 depending on your setup 2 Replace with the Anode of your external LED string connect to the post on the right 3 If needed connect the post on the left also with the anode of your external LED string Table 1 ABSOLUTE MAXIMUM RATINGS a O O o Stresses exceeding those listed in the Maximum Ratings table may damage the device If any of these limits are exceeded device functionality should not be assumed damage may occur and reliability may be affected Table 2 RECOMMENDED
8. se are programmed using resistors to ground on the RSTOP and RTAIL pins Control of the STOP and TAIL functions use an external network of diodes with the STOP pin LED open string reporting is reported on the DIAG pin The DIAG pin also serves to reset a latched off event System power distribution is accomplished using voltage feedback on the top LED anode programming a set voltage in the system to allow a split between the IC and the ballast transistor Semiconductor Components Industries LLC 2015 1 November 2015 Rev 0 ON Semiconductor www onsemi com EVAL BOARD USER S MANUAL TAIL Mode STOP Mode Figure 1 Evaluation Board Picture Publication Order Number EVBUM2328 D NCV7681AGEVB LED Loads Ballast OUT VP Drive OUT2 VBAT mao tT OUT6 RSTOP OUT7 RTAIL OUT8 GND FB NCV7681 STOP TAIL Selection amp Activation __ Ballast Transistor Voltage Regulation Feedback Figure 2 Focus Demonstration STOP The STOP function displays the highest system output current at 100 duty cycle Using the STOP switch activates this function The current is programmable with a resistor on the RSTOP pin to ground Jumper J3 provides isolation of pin7 of the NCV7681 allowing access to the pin for alterative selection of output current The range of programmability is from 15 mA to 100 mA using the equation _ 150 OUT RSTOP where RSTOP is the resistor val
9. sistor Selection 2 yellow boxes Dark Blue 2 STOP programming jumper Light Green DIAG RESET Not functional in the NCV7681A Only functional in the NCV7681L Bright Red DIAG jumper post Brown Feedback post FB Red 2 TAIL programming jumper post Dark Green VP post Purple 2 Vstrinc post Light Blue 4 OUT1 OUT8 open circuit jumpers www onsemi com 4 NCV7681AGEVB OPERATIONAL GUIDELINES The material necessary to successfully use the evaluation board is listed below e NCV7683 Evaluation Board e 14 V Power Supply Capable of drive 1 A Configure the Board Typical Board Configuration with On Board Components 1 Connect all jumpers on the board with the exception of Jumper 18 J15 J17 should be to the left 2 Connect the 14 V power supply 3 Turn on the power supply Increasing the LED Current Change the current programming resistor Reference the STOP section Change the Duty Cycle Change the duty cycle programming resistor Reference the TAIL section DIAG The on board LED will illuminate when DIAG reports a fault Reporting can be taken off board after removing the DIAG jumper J5 Use External LEDs Reference the External LEDs section for instructions SCHEMATIC TAIL 20 J18 1 Vstring J1 O VP Vbat 2 1 Swi D25 O NTD2955 4 TAIL MRA4003 STOP 1K O D26 sw2 STOP MRA4003 J2 GND R8 R1 4 99K 10K D27 led_diode ouT2
10. ue 100 90 80 70 60 50 40 30 20 10 lour OUTPUT CURRENT mA 0 1 2 3 4 5 6 7 8 9 10 RSTOP kQ Figure 3 lour vs RSTOP TAIL The TAIL function displays a lower equivalent output current in the system This provides a lower illumination of the LEDs This is achieved with a varied duty cycle of the output current The duty cycle is programmable with a resistor on the RTAIL pin to ground Jumper J4 provides isolation of pin 6 of the NCV7681A allowing access to the pin for alternative selection of output duty cycle current The range of programmability is from 0 duty cycle to 100 duty cycle using the equation RTAIL 1 8 x RSTOP DC 0 22 where DC duty cycle expressed in fractional form 100 90 80 70 60 50 40 30 20 10 DUTY CYCLE 0 1 2 3 4 5 6 7 RTAIL kQ Figure 4 Duty Cycle vs RTAIL www onsemi com NCV7681AGEVB DIAG The DIAG pin of the NCV7681A provides system feedback for conditions 1 Output open circuit 2 Set Back Current Limit down 20 3 Thermal shutdown 4 RSTOP Current Limit 4 Remove your selection of Jo J13 OUTx y 5 Connect the Cathode of your external LED string connect to the post on the right The operation of the NCV7681A evaluation board works as a standalone presentation for the customer Jumpers are provided for flexibility of customer s
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