EVBUM2131 - NCP1230 90 Watt, Universal Input Adapter Power
Contents
1. 2 Vclamp Vclamp Vo n Rclamp p le Ipk2 Freq 2 700 700 19 7 6 77 Rclamp 110 kQ 7 3 972 65 Where Vo lt the output voltage Vf the forward voltage drop across the output diode n is the transformer turns ratio 6 77 Ie is the transformer turns ratio of 7 uH The power dissipation in the clamp resistor is Vclamp Vclamp Vo n PRclamp 0 5 Ipk2 le Freq PRclamp 0 5 3 972 7 65 700 700 19 7 6 77 44W The snubber capacitor can be calculated from the following equation See Application Note AN1679 D for details of how the snubber eguations were derived 6 Vclamp Vripple Freq Relamp 700 a C6 20 65 110 0 005 uF After the initial snubber was calculated the snubber values were tuned in the circuit to minimize ringing and minimize the power dissipation As a result the final circuit values are Rclamp uses three 100 kQ 33 kQ equivalent 2 0 W resistors used in parallel and C6 is 0 01 uF 1000 V Refer to Figure 2 for a scope waveform of the Drain to source voltage at full load and high line Tek Run 10 0MS s Sample al M5 00us Ch3 T 670 V 12 May 2004 i 100v 11 08 02 Figure 2 Current Sense Resistor Selection The input to the current sense amplifier is clamped to 1 0V typical The current sense resistor should be calculated at 125 of the full rated load to be sure that under2. opto and is nominally 1 0 but over time the CTR will degrade so analysis of the circuit with the CTR 0 5 is recommended Rfb is the internal pull up resistor of the NCP1230 and it is a nominal 20 kQ Standby Power To minimize the standby power consumption the output voltage sense resistor divider network was select to consume less than 10 mW _ RIO 74 08 M Vo are Az 19 55259 9 V The Standby power consumption is _ Vo2 _ 192 _ Rtotal 57400 e MW Standby power calculation P R22 2 R22 12ma 2k 2 mW P TL431 Vo V R22 Vopto 1 ma 17 V 1 ma 17 mW Control Loop Two methods were used to verify that the Demo Board loop was stable the results are shown below The first method was to use an Excel Spreadsheet using the previously derived eguations which can be down loaded from the ON Semiconductor website www onsemi com The results from the Excel Spreadsheet are shown below At full load and 200 Vdc 200 Vdc is the minimum voltage being supplied from the PFC the loop gain crosses zero dB at approximately 1 2 kHz with approximately 100 of phase margin The second method was to model the NCP1230 Demo Board in PSPICE The result can be seen in Figure 7 Because parasitic elements can be added to the PSPICE model it was more accurate at high freguencies The results from the PSPICE model at low freguencies shows similar results the loop gain crosses zero dB at approximately 1 2 kH
3. 100ma NA SOT 23 Semiconductor BAS19LT1G No Yes ON D4 1 Diode ultra fast 600 V 1 A NA DO41 Semiconductor MUR160 No Yes D8 D9 D10 ON D11 4 Diode rectifier 1000 V 3 A NA DO201AD Semiconductor 1N5408G No Yes ON D12 1 Diode ultra fast 600 V 4A NA DO201AD Semiconductor MUR460 No Yes D13 ON D15 2 Diode rectifier 800 V 1 A NA DO41 Semiconductor 1N4006 No Yes D17 D18 2 Zener Diode SM 18 V 0 3 W NA SOT 23 Vishay AZ23C18 Yes Yes http onsemi com 13 Table 11 NCP1230 EVALUATION BOARD BILL OF MATERIALS NCP1230GEVB Substi RoHS Desig Toler Manufacturer Part tution Com nator GTY Description Value ance Footprint Manufacturer Number Allowed pliant ON D19 1 Diode schottky 100 V 20A NA TO220AB Semiconductor MBR20100CTG No Yes 10mm x Fi 1 Brick Fuse 250 Vac 2A NA 2 5mm Bussman 1025TD2 Yes Yes J2 J4 2 PCB Connector 10 A 300 V NA 5 08 mm Weidmuller 171602 Yes Yes 13 mm x L1 1 Inductor 2 2 uH 7 5 A 10 9 mm Coilcraft DO3316P 222ML Yes Yes L2 L3 2 Inductor 100 uH 2 5 A 10 1315 TDK TSL1315 101K2R5 Yes Yes Cooper L4 1 PFC Indcutor 400 uH 5 A 20 NA Electronics CTX22 16816 Yes Yes Common Mode L5 1 Inductor 508 uH 3 A 30 NA Coilcraft E3506 AL Yes Yes Q1 1 MOSFET 0 8 92 800 V 11 A NA TO220 31 Infineon SPP11N80C3 Yes Yes Q2 1 MOSFET 0 8 92 650 V 7 3 A NA TO220 31 Infineon SPPO7N60C3 Yes Yes ON Q3 1 Bipolar transistor 60 V 0 6 A NA SO
4. D http onsemi com 9 NCP1230GEVB ONO K 99A Odd OGA AL DCH NL 6LH 909NZ0ddS O9ANN ola 09Z 9W LN v1 9OVSNI 907SNL an U0 90bGNL 90PSNL Figure 10 NCP1230 Demo Board Schematic PFC section http onsemi com 10 NCP1230GEVB L900LOcHdW 200X vvSL9HdS c sl Ab Lcd O08N LlddS LD D eta LUIGUIvg 91d 00L GO Wine live 00H A001 BLY 6cH O9LHNIN Hiozz ga ooz 4u0 L D ddool go 1OS V2062LdNW 006 Sed vc OGA 99A Odd DC section Figure 11 DC onsemi com http 11 NCP1230GEVB Table 7 Voltage Regulation and Efficiency Table 9 Standby Power Condition Requirement Pin Pin Measured Test Vac input mW mW Table 10 Vendor Contact List http onsemi com 12 Table 11 NCP1230 EVALUATION BOARD BILL OF MATERIALS NCP1230GEVB Substi RoHS Desig Toler Manufacturer Part tution Com nator GTY Description Value ance Footprint Manufacturer Number Allowed pliant ON U9 1 Flyback Controller 18V 0 5 A NA SOIC 8 Semiconductor NCP1230D65R2G No Yes ON U2 1 PFC controller 16V 0 6A NA SOIC 8 Semiconductor MC33260DG No Yes Programable ON U12 1 reference 2 5 V NA SOIC 8 Semiconductor TL431ACDG No Yes U4 1 Optocoupler 70 V 50 Ma NA UL1577 Vishay SFH615A 3 Yes Yes C1 Ceramic chi
5. E _ Vac Vac 2 E Vo Vac Ipk Lp 2 SE 2 85 85 2 FREE 200 85 3 86 AM The value used is 400 uH Where 1 Eis Tp Freqmin 30 33 33 usec Vomin 200 Vdc 85 Vac input Vac 85 Vac The oscillator timing capacitor is calculated by the following formula _ 4 Vo Kosc Lp Pin CT Cint Ro Vpk2 4 2002 6400 400 11 pre SS ES EE 22 1202 Where Kosc 6400 Ro 2 0 MQ feedback resistor The CT value used is 820 pF Refer to the ON Semiconductor website for Application Note AND8123 D for additional MC33260 application information and the Excel based development tool DDTMC33260 D Startup Circuit Description The High Voltage pin pin 8 of the NCP1230 controller is connected directly to the high voltage DC bus When the input power is turned on an internal current source is turned on typically 3 0 mA charging up an external capacitor on the Vcc pin When the Vcc capacitor is above VCCoff the current source is turned off and the controller delivers output drive pulses to an external MOSFET Q1 The MOSFET Ol drives the primary of the transformer T1 The transformer has two additional windings the auxiliary winding which provides power to the controller after the power supply is running and the secondary winding which provided the 19 Vdc output power Transformer The transformer primary inductance was selected so the current would be discontinuous under all operating conditio
6. NCP1230GEVB NCP1230 90 Watt Universal Input Adapter Power Supply Evaluation Board User s Manual General Description The NCP1230 implements a standard current mode control architecture It s an ideal candidate for applications where a low parts count is a key parameter particularly in low cost adapter power supplies The NCP1230 combines a low standby power mode with an event management scheme that will disable a PFC circuit during Standby thus reducing the no load power consumption The 90 W Evaluation Board demonstrates the wide range of features found on the NCP1230 controller The NCP1230 has a PFC Vcc output pin which provides Vcc power for a PFC controller or other circuitry The PEC Vec pin is enabled when the output of the power supply is up and in regulation In the event that there is an output fault the PEFC Vec pin is turned off disabling the PFC controller reducing the stress on the PFC semiconductors In addition to excellent no load power consumption the NCP1230 provides an internal latching function that can be used for over voltage protection by pulling the CS pin above 3 0 V Features e Current Mode Control e Lossless Startup Circuit Operation Over the Universal Input Range Direct Connection to PFC Controller Low Standby Overvoltage Protection Ml a Figure 1 Evaluation Board Photo Semiconductor Components Industries LLC 2012 August 2012 Rev 1 ON Semiconductor http o
7. T 23 Semiconductor MMBT2907ALT1G No Yes R1 R3 2 Resistor 0 4 Q 1 W 1 2512 Vishay WSL2512R4000FEA Yes Yes R2 R18 14 10 mm R29 3 Resistor 100k 3W 5 x 4 57 mm Vishay CPF3100k00JNE14 Yes Yes R4 1 Resistor 49 9 kO 1 8 W 1 0805 Vishay CRCW08054992FNEA Yes Yes R5 R6 R16 3 Resistor 1391W 1 2512 Vishay CRCW25121R30FNEA Yes Yes R7 1 Resistor 4 7 kO 1 8 W 5 0805 Vishay CRCW8054700RJNEA Yes Yes R10 1 Resistor 7 42 kO 1 8 W 1 0805 Vishay CRCW08057421FNEA Yes Yes R13 1 Resistor 209 1 4W 5 1206 Vishay CRCW120620R0JNEA Yes Yes R17 1 Resistor 8 06 kO 1 8 W 1 0805 Vishay CRCWO8058K06FKEA Yes Yes R19 6 10 mm R20 2 Resistor 1 MQ 1 8 W 1 x 2 29 mm Vishay CMF551004FKEK Yes Yes R21 R22 2 Resistor 1 kO 1 4 W 1 1206 Vishay CRCW12061K00FKEA Yes Yes R24 1 Jumper 22 AWG NA NA NA Any NA Yes Yes R25 1 Resistor 200 Q 1 4 W 5 1206 Vishay CRCW1206200RJNEA Yes Yes R26 1 Resistor 10 kQ 1 4 W 5 1206 Vishay CRCW120610KOJNEA Yes Yes R27 1 Resistor 4 7 Q 1 4 W 5 1206 Vishay CRCW12064R7JNEA Yes Yes R28 1 Resistor 200 Q 1 4 W 5 1206 Vishay CRCW1206200RJNEA Yes Yes Flyback 220 uH 3 3 Cooper T1 1 Transformer Apk NA NA Electronics CTX22 16134 Yes Yes 4 x H1 1 Shoulder Washer NA NA 0 031 Keystone 3049 Yes Yes 0 86 x H2 1 Insulator NA NA 0 52 Keystone 4672 Yes Yes H3 H4 H5 3 Heatsink NA NA TO 220 Aavid 590302B03600 Yes Yes http onsemi com 14 NCP1230GEVB ON Semiconductor and Q are registered trademarks of Semiconductor Compone
8. all operating conditions the power supply will be able to deliver the full rated power Po 90 1 25 112 5 W Pin PO 112 5 140 63 W eff 0 80 2 140 63 1V 1 0 2 Q was used To reduce the power dissipation in the sense resistor two 0 4 Q resistors were used in parallel Overvoltage Protection The NCP1230 has a fast comparator which only monitors the current sense pin during the power switch off time If the voltage on the current sense pin rises above 3 0 V typical the NCP1230 will immediately stop the output drive pulses and latch off the controller The NCP1230 will stay in the Latch Off mode until Vcc has dropped below 4 0 V This feature allows the user to implement several protection functions for example Overvoltage or Overtemperature Protection The Auxiliary winding of the Flyback transformer T5 can be used for overvoltage protection because the voltage on the Auxiliary winding is proportional to the output voltage http onsemi com 4 NCP1230GEVB To implement Overvoltage Protection OVP a PNP transistor is used to bias up the current sense pin during the NCP1230 controller off time refer to Figure 3 The base of the PNP transistor is driven by the NCP1230 drive output pin 5 if the Auxiliary winding voltage increases above the Zener diode D1 breakdown voltage 13 V current will flow through Q3 biasing up the voltage on the current sense pin Using typical component values if the voltag
9. based upon on the peak inverse voltage and the diodes average forward current The peak inverse voltage across the secondary of the transformer is Vin PIV Vo 400 _ Ply 6 77 19 78 Vpk The average current through the diode is Po _ 90 lavg Vo 19 4 74A An MBR20100CT Schottky diode was selected it is rated for a Vrrm of 100 V with an average forward current of 10A Power Switch A MOSFET was selected as the power switching element Several factors were used in selecting the MOSFET current voltage stress VDS and Rps on The rms current through the primary of the transformer is the same as the current in the MOSFET which is 1 45 Arms The MOSFET selected is manufactured by Infineon part number SPP11N80C3 It is rated for 800 VDS and 11 Arms with an Rpsgon of 0 45 Q http onsemi com NCP1230GEVB Snubber The maximum voltage across the MOSFET is Vpk Vin max Vo Vin Vpk 400 19 0 7 6 77 534V This calculation neglects the voltage spike when the MOSFET turns off due to the transformer leakage inductance The spike due to the leakage inductance must be clamped to a level below the MOSFETs maximum VDS To clamp the voltage spike a resistive capacitive diode clamp network was used to prevent the drain voltage from rising above Vin Vo Vf n Vclamp The desired clamp voltage is 700 V this provides a safety margin of 100 V The first step is to calculate the snubber resistor
10. e NCP1230 does have a leading edge blanking circuit but it is a good design practice to add an external filter The time constant of the filter must be significantly higher than the highest expected operating frequency but low enough to filter the spike Output Control Feedback theory states that for the control loop to be stable there must be at least 45 of phase margin when the loop gain crosses cross zero dB The following equations derive the Flyback converter transfer function while operating in the discontinuous continuous mode Vo2 Po Ro Where Po is the maximum output power Vo is the output voltage Ro is the output resistance 1 w Un P gt Ipk Lp f Where I is the peak primary current Lp is the transformer primary inductance F is the switching frequency of the controller Vo 1 OSI Lp Ro 2 Ipk Lp f Vo Ro f Lp Eid i 2 Ip Rs VE i Ip Rs 3 Where Ip is the peak primary current Rs is the current sense resistor Vc is the control voltage 3 the feedback input voltage is divided down by a factor of three Combining equations the open loop gain is Vo _ jRo Lp f ad i 2 i Ipk Rs VE i Ipk Rs 3 Vc 3 Rs Ipk http onsemi com NCP1230GEVB Ro Lp f ve i n d Ipk Rs 3 With current mode control there is pole associated with the output capacitor s and the load resistors In this application there are four 2200 uF capacitors in parallel TE 1 nCoRo
11. e on the Auxiliary winding reaches 16 5 V 3 5 V above the nominal voltage the NCP1230 will latch off through the CS input pin 3 OVPthreshold Vz D1 VceQ3 CSlatchoff 13V 0 5V 3 0V 16 5V A 13 V Zener diode was selected to have the controller Latch Of prior to having Vcc reach its maximum allowable voltage level 18 V Vaux Figure 3 Overvoltage Protection Circuit Overtemperature Protection To implement Overtemperature Protection OTP shutdown the Zener diode can be replaced by an NTC refer to Figure 4 or an NTC can be placed in parallel with the Zener diode to have OVP and OTP protection When an overtemperature condition occurs the resistance of the NTC will decrease allowing current to flow through the PNP transistor biasing up the Current Sense pin Vaux NTC MMBT2907A SOT Q3 NCP1230 Figure 4 Overtemperature Protection Circuit Slope Compensation A Flyback converter operating in continuous conduction mode with a duty cycle greater than 50 requires slope compensation In this application the power supply will always be operating in the discontinuous mode so no slope compensation is required The resistor R21 and capacitor C24 form a low pass filter suppressing the leading edge of the current signal Typically the leading edge of the current will have a large spike due to the transformer leakage inductance If the spike is not filtered it can prematurely turn off the MOSFET Th
12. ended or unauthorized application Buyer shall indemnify and hold SCILLC and its officers employees subsidiaries 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 P O Box 5163 Denver Colorado 80217 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 Wa 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 EVBUM2131 D
13. ns As a result the total switching period Ton Toff must be less than or egual to 1 freguency The following assumptions were used in the design process Dmax 0 4 Duty Cycle V de bus 200 Vdc input with Vin 85 Vac Efficiency 0 80 Freq 65 kHz Vo lt 19 V Vf 0 7 Po 90 W Pin 2 90 112 5 W Pin 1125 _ lavg Vin 200 0 566 2 Pin Lp a 2 lavg F EK 2 112 Lp ze 732436 uH g In this application the primary inductance used is 220 uH This takes into consideration the transformer tolerances and to minimize the transformer size Once the primary inductance has been calculated the next step is to determine the peak primary current Pin 3 Ipk2 Lp f Pin 2 Ipk SESCH 2 112 5 Ipk 220 65 gt 8 97 Apk The following calculations are used to verify that the current will be Discontinuous under all operating conditions Tp Ton Toff gt freg _ Lp Ipk Ton Win Ls lopk Toff vor _ Lp Ipk Ls lopk A vin r Where _ Lp Ls F n is the transformer turns ratio 6 77 220 3 97 4 8 27 22 Tp 200 1 q9 07 E With a primary inductance value of 220 uH Ton Toff is less than the controller switching period An Excel spreadsheet was designed using the above equation to help calculate the correct primary inductance value visit the ON Semiconductor website for a copy of the spreadsheet http onsemi com NCP1230GEVB One method for calculating the transformer tur
14. ns ratio is to minimize the voltage stress of the MOSFET Vps due to the reflected output voltage VDSmax Vinmax n Vo Vf Vspike In this application an 800 V MOSFET was selected The goal for safety purposes is to limit VpSmax at high line including the Vspike to 700 V To limit the power dissipation in the snubber clamp refer to the section in the Applications Note titled Snubber Vspike is clamped at 167 V Ge VDSmax Vinmax Vspike Vo Vf 700 400 167 _ n 197 6 77 The NCP1230 requires that the controller Vcc be supplied through an auxiliary winding on the transformer The nominal supply voltage for the controller is 13 Vdc Vaux 1 D max aux vin D max no 1371 04 aux 200 0 4 The supply voltage to the controller may be higher than the calculated value because of the transformer leakage inductance The leakage inductance spike on the auxiliary winding is averaged by the rectifier D2 and capacitor CS Because of this an 18 V Zener diode D18 refer to the Demo Board Schematic Figure 10 is connected from the Vcc pin to ground To limit the current into the Zener diode a 200 Q resistor is placed between C5 and the Vcc pin R28 ON Semiconductor recommends that the Vcc capacitor be at least 47 uF to be sure that the Vcc supply voltage does not drop below Vecmin 7 6 V typical during standby power mode and unusual fault conditions 0 128 The transformer primary rms curre
15. nsemi com EVAL BOARD USER S MANUAL Design Specification This Demo Board is configured as a two stage adapter power supply The first stage operates off of the universal input 85 265 Vac 50 60 Hz using the MC33260 Critical Conduction Mode controller in the Boost Follower mode The output voltage from the Boost Follower when Vin is 85 Vac is 200 V and as the input line increases to 230 Vac the output of the Boost Follower will ramp up to 400 Vdc The second stage of the power supply features the NCP1230 driving a flyback power stage The output of the second stage is 19 Vdc capable of 90 W of output power It is fully self contained and includes a bias supply that operates off of the Auxiliary winding of the transformer Table 1 EVALUATION BOARD SPECIFICATIONS Betten Sma win we Dome w _ ees 1 m Standby Power mW 150 Vin 230 Vac Pin Short Circuit Load mW 100 Vin 230 Vac Pin with 0 5 W Load mW Vin 230 Vac PFC The MC33260 is configured as a Boost Follower operating from the universal input line The PFC section was designed to provide approximately 116 W of power lok 2 J2 Pin max p Vac 2 2 116 Ipk a gt 3 86 A Publication Order Number EVBUM2131 D NCP1230GEVB The MC33260 is a Critical Conduction Mode controller as a result the switching freguency is a function of the boost inductor and the timing capacitor In this application the minimum operating freguency is 30 kHz 2 G
16. nt is Irms Ipk fon 3 97 cu 1 45 Arms The transformer secondary rms current is Irms sec Ipk prim n 12 3 97 6 77 K 12 02 Arms The transformer for the Demo Board was manufactured by Cooper Electronics Technologies www cooperET com part number CTX22 16134 The designer should take precautions that under startup conditions the transformer will not saturate at the low input ac line 85 Vac and full load conditions The above calculation assumed that the adapter was running and the PFC front end was enabled Output Filter One of the disadvantages of a Flyback converter operating in the Discontinuous mode is there is a large ripple current in the output capacitor s As a result you may be reguired to use multiple capacitors in parallel to handle the ripple Current cap ripple lorms2 lo2 cap ripple 12 022 4 742 11 04 A Ton 0 4 6 15 usec 1 4 frequency 65000 _ lorms T Ton Ca Vripple Where Vripple 50 mV 12 02 15 38 9 23 ES 0 05 In the 90 W Adapter design four 2200 uF 8800 uF total capacitors C2 C3 C14 and C15 were required in parallel to handle the ripple current A small LC filter has been added to the output of the power supply to help reduce the output ripple The cut off frequency for the filter is 1 478 uF 1 1 fo 15 6 kHz 2nvLC 27 2 2 47 L1 2 2 uH C8 47 uF Output Rectifying Diode The rectifying diode was selected
17. nts Industries LLC SCILLC SCILLC owns the rights to a number of patents trademarks copyrights trade 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 unint
18. p C19 2 capacitor 0 1 uF 50 V 10 0603 Vishay VJ0603Y104KXAA Yes Yes C2 C3 C14 Electorlytic 16 0 mm C15 4 Capacitor 2200 uF 25 V 20 x 25 0 mm Vishay EKBOOJG422F00 Yes Yes Electorlytic 6 3 mm x C5 1 Capacitor 100 uF 35 V 20 11 0 mm Vishay EKBOOBA310F00 Yes Yes C6 1 Cap Ceramic 0 01uF 1000V 10 Disc Vishay 562RZ5UBA102E103M Yes Yes Cap Aluminum 5 0 mm x C7 C8 2 Elec 47 uF 25 V 20 11 0 mm Vishay EKBOOAA247F00 Yes Yes Capacitor Y2 5 3 mm x C10 1 class 2 2 nF 250 V 20 10 3 mm Vishay F1710 222 1000 Yes Yes C11 Capacitor X2 8 3 mm x C17 2 class 0 1 uF 300 V 10 17 8 mm Vishay F1772 410 3000 Yes Yes Ceramic chip C12 1 capacitor 0 068 uF 50 V 10 0603 Vishay VJ0603Y683KXAA Yes Yes Ceramic chip C13 1 capacitor 470 pF 50 V 10 0603 Vishay VJ0603471KXAA Yes Yes Ceramic chip C18 1 capacitor 680 pF 50V 10 0603 Vishay VJ0603Y681KXAA Yes Yes Cap Ceramic C20 1 chip 0 047 uF 16V 10 0805 Vishay VJ0805Y473KXJA Yes Yes 13 0 mm x C22 1 Capaitor X2 class 0 47 uF 300 V 10 31 3 mm Vishay F1772 447 3000 Yes Yes 25mm x C23 1 Cap Aluminum 150uF 450Vdc 20 40mm Panasonic ECOS2WP151CA Yes Yes Ceramic chip C24 1 capacitor 100 pF 50 V 10 0805 Vishay VJ0805100KXAA Yes Yes Ceramic chip C25 1 capacitor 1 0 nF 50 V 10 0805 Vishay VJ0805Y102KXAA Yes Yes Capacitor X2 10 3 mm C27 1 class 0 22 uF 300 V 10 x 26 3 mm Vishay F1772 422 3000 Yes Yes D1 1 Zener Diode SM 13 V 0 3 W NA SOT 23 Vishay AZ23C13 Yes Yes D2 ON D16 2 Diode signal 75V
19. the NCP1230 provides 19 Vdc to the load Vary the load and input voltage Verify that the output voltage is within the minimum and maximum values as shown in Table 4 7 To verify total harmonic distortion THD first shut off the ac power supply GD 8 Connect the Voltec Precision Power Analyzer as shown in Figure 9 9 Turn on the ac source to 115 Vac at 60 Hz and set the electronic load to 90 W Only measure the THD at full load 10 Verify that the current Harmonics THD are less than the maximum vales in Table 5 11 Verify that the PF is greater than the minimum values in Table 5 12 Set the ac source output to 230 Vac at 60 Hz 13 Verify that the current Harmonics THD are less than the maximum vales in Table 5 14 Verify that the PF is greater than the minimum values in Table 5 15 Set the ac source to 115 Vac set the load to O Adc and measure the standby power refer to Table 5 for the maximum acceptable input power 16 Set the ac source to 230 Vac and refer to Table 5 for the maximum input power Table 3 EXPECTED VALUES FOR VARYING INPUT VOLTAGES AND LOADS Vin Vo Vdc Vo Vdc Vo Vdc THD No Load 45 W 90 W Table 3 shows typical values the initial set point 19 0 Vdc may vary http onsemi com NCP1230GEVB Table 4 REGULATION Vin do Vomin Vomax IO Eff a Vdc BE c c R ZNE TE MR NND 230 Table 5 STAND BY POWER Table 6 POWER FACTOR AND TH
20. x 8800 3 9 The secondary filter made up of L1 and C8 does not affect the control loop because we are sensing the output voltage before the LC network In addition to the pole there is a zero associated with the output capacitor s and the capacitors esr The esr of each capacitors is 0 022 Q from the data sheet 9 3 Hz 1 1 fz ZnCo 68 6 26 6800 E 3 3 kHz A small 0 47 nF capacitor C25 is connected from the feedback pin to ground to reduce the switching noise on the feedback pin Care must be taken not to have too large a capacitor or a low frequency pole may be created in the feedback loop Output Voltage Regulation The output voltage regulation is achieved by using a TI 431 on the secondary side of the transformer The output voltage is sensed and divided down to the reference level of the TL431 2 5 V typical by the resistive divider network consisting of R4 and R10 The TL431 requires a minimum of 1 0 mA of current for regulation Vo V opto _ 19 1 18k Ropto R22 IT mA 1 mA In this application R22 was changed to 1 0 kQ to minimize the stand by power consumption When the power supply is operating at no load there may not be sufficient current through the optocoupler LED so a resistor R7 is placed in parallel A 4 7 kQ resistor was selected The optocoupler gain is AVfb _ Rfb CTR 20 10 AVC Ropto 1 20 dBgain 20log20 26 dB CTR is the current transfer ratio of the
21. z with about 90 of phase margin Loop Gain Plot 60 a nr O 10 100 1000 10000 FREQUENCY IN Hz 100000 Figure 5 Excel Spreadsheet Loop Gain http onsemi com NCP1230GEVB Loop Phase Margin 180 180 140 100 100 60 p 20 T a 20 0 60 100 M0 100 80 10 Hz 100 Hz 1 0 kHz 10kHz 100 kHz 10 100 1000 10000 10000C a DB V FB P V FB FREOUENCY FREOUENCY Figure 6 Excel Spreadsheet Phase Margin Figure 7 SPICE Phase Gain R7 D4 outi L1 NCP1230 AV U7 XFMR 46 mursio M 2 2 uH NCP1230 averaged RATIO 0 1477 Ri 4 7 k MOC8101 R4 7 4k Figure 8 AC Freguency Response SPICE Model http onsemi com 7 NCP1230GEVB Evaluation Board Test Procedure VOLTEC Precision Power Analyzer Alo AH VLo vn TRIATHLOM Precision AC Source 1115Y KIKUSUL Electronic load Figure 9 NCP1230GEVB Test Setup Table 2 TEST EQUIPMENT ac Source 85 265 Vac 47 64 Hz Variable Electronic Load Digital Multimeter Voltec Precision Power Analyzer Test Setup 1 Connect the ac source to the input terminals J4 2 Connect a variable electronic load to the output terminals J2 the PWB is marked for the positive output and for the return 3 Set the variable electronic load to 45 W 4 Turn on the ac source and set it to 115 Vac at 60 Hz 5 Verify that
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