NCP1351PRINTGEVB Manual
Contents
1. paeoqowag 49JUTIJA TSLETHIN Figure 10 SMD Components hitp onsemi com 6 NCP1351PRINTGEVB U1 DFO5M e WONZCCH Z x6 fa e ELF 25F108A 1N4007 D13 C13 14 100 u Jitter 330 k 330 k 10n C12 1N4007 R15 D3 X11 C23 IRFIBEN6O 2 2n X4 1k R18 2 7k R19 R28 3 24k 10k R22 R21 3 65 k 200k R31 16V 32 V GND Figure 11 Schematic for the NCP1351 40 W Printer Evaluation Board http onsemi com 7 NCP Table 4 BILL OF MATERIAL FOR THE NCP1351 40 Qty Description Value Tolerance 5 SMD Capacitor 100 nF 50 V C3 1 Electrolytic 4 7 uF SOV 20 Capacitor 1 SMD Capacitor 180 pF 50 V 5 C7 1 Electrolytic 47 uF 50 V 20 Capacitor 1 SMD Capacitor 10 nF 50 V 5 1 SMD Capacitor 1 5 uF 10 1 Film Capacitor 10 nF 630 V 5 1 Electrolytic 100 uF 400 V 20 Capacitor 1 X2 Capacitor 330 nF 250 Vac 20 Electrolytic 1 000 uF 50 V Capacitor 100 uF 50 V 20 1 000 uF 25 V 100 uF 25 V 20 2 2 nF 250 Vac 20 Electrolytic Capacitor Electrolytic Capacitor Electrolytic Capacitor Y1 Capacitor SMD Resistor i 0 Q 0 25 W 596 200 mA 200 V High voltage Switching Diode 12. compresses the peak current setpoint as the load becomes lighter When the current reaches 30 of the nominal value the compression stops and the off duration keeps expanding towards low frequencies Low Standby power The frequency reduction technique offers an excellent solution for designers looking for low standby power converters Also compared to the skip cycle method the smooth off time expansion does not bring additional ripple in no load conditions the output voltage remains quiet Semiconductor Components Industries LLC 2012 October 2012 Rev 0 ON Semiconductor hitp onsemi com EVAL BOARD USER S MANUAL Natural Frequency Dithering The quasi fixed tp mode of operation improves the EMI signature since the switching frequency varies with the natural bulk ripple voltage Extremely Low Start up Current Built on a proprietary circuitry the NCP1351 startup section does not consume more than 10 uA during the startup sequence The designer can thus easily combine startup time and standby consumption Overload Protection Based on Fault Timer Every designer knows the pain of building converters where a precise over current limit must be obtained When the fault detection relies on the auxiliary Vcc the pain even increases Here the NCP1351 observes the lack of feedback current and starts a timer to countdown At the end of its charge the timer either triggers an auto recovery sequence auto
3. 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 Fax 303 675 2176 or 800 344 3867 Toll Free USA Canada Japan Customer Focus Center Email orderlit onsemi com Phone 81 3 5817 1050 For additional information please contact your local Sales Representative EVBUM2150 D
4. restart B and D versions or permanently latches off A and C On C and D versions the fault timer is started at an output power corresponding to 60 of the maximum deliverable power to allow transient peak power delivery Latch Fault Input A dedicated input lets the designer externally trigger the latch to build additional protections such as over voltage OVP or over temperature OTP Figure 1 NCP1351 Evaluation Board Publication Order Number EVBUM2150 D NCP1351PRINTGEVB The Schematic The design must fulfill the following specifications Input Voltage 88 265 Vac Output Voltage 16 V 0 625 Aand32 V 1A Nominal 40 W with Transient 80 W Peak Power Capability during 40 ms and 62 W Peak during 400 ms Over Power Protection below 100 W for the Whole Input Voltage Range LPS Latched Short circuit Protection Latched Over voltage Protection Latch Recovery Time below 3 s Brown out Protection Start up Time below 3 s In order to deliver the peak output power the NCP1351 will increase its switching frequency up to the upper limit set by the Cr capacitor To not jeopardize the EMI test compliance the switching frequency should be kept below 150 kHz We will choose 100 kHz to have a good margin As a result the switching frequency at nominal load will be around 50 kHz Since we need to deliver 80 W of transient peak power while ensuring the power will never be above 100 W we will use the C version of NCP135
5. 1 specially tailored for this kind of application When the controller detects a need for a frequency higher than 60 kHz implying an overload condition it will start to charge the timer capacitor if the overload disappears the timer capacitor goes back to zero If the fault remains the timer capacitor voltage reaches 5 V and latches off the controller During the fault condition the power supply will anyway deliver the output power while the switching frequency is below its maximum value of 100 kHz The transformer has been derived using the Excel spreadsheet available from the ON Semiconductor website which also gives transformer parameters We came up to the following values Lp 270 uH Np Ns 1 0 2 Np Naux 1 0 2 Is 73 A The transformer has been manufactured by Coilcraft www coilcraft com The leakage inductance is kept around 3 of the primary inductance leading to a good efficiency and reduced losses in no load conditions The schematic appears on Figure 2 The converter operates in DCM at nominal power and for peak power it goes CCM with close to 50 duty cycle at low mains and stays CCM at high line Figure 2 The Simplified 40 W Printer Board Featuring the NCP1351 Controller hitp onsemi com 2 NCP1351PRINTGEVB Two 330 KQ resistors in series with a 60 V zener diode ensure a clean start up sequence with the 4 7 uF capacitor C3 not from the bulk capacitor as it is usually done but from the fully re
6. A 600 V Fast recovery Rectifier Schottky Rectifier 20 A 100 V 17 V 0 5 W 60 V 0 5 W 200 mA 75 V Zener Diode 5 Zener Diode 5 i Switching Diode 6 2 V 0 5 W 1 A 1 000 V Zener Diode 5 Standard Rectifier 13 4 C W C W 1 Heatsink 2 TO 220 Heatsink 24 HS2 HS3 U1 1 Rectifier Bridge 1 A 600 V CMOS IC N Optocoupler x EN 2 x 15 mH 1 A Common mode Choke Shunt Regulator 2 5 36 V 5 Power 3 A 600 V MOSFET N Channel Transformer 230 Vac 2 A 250 Vac 10 uH 4 7 wH 4 3 A 15 Q 0 25 W Connector Fuse SMD Inductor Inductor 20 SMD Resistor 5 h 1351PRINTGEVB Substitution Allowed Manufacturer W PRINTER EVALUATION BOARD Part Number SOD 1206 VJ1206V104KXAA Radial SOD 1206 VJ1206A181KXAA OD 5mm OD 5mm Radial EKXG401ELL101MMN3S OD 20 mm Ye i es ee Radial Panasonic EEUEB1H101S Ves Ves OD10mm cael Radial Panasonic EEUEB1E101 Ves Ves OD10mm SOD 1206 CRCW12060000Z0EA SOT 23 ON Semiconductor BAS20LT1G ON Semiconductor 1N4937G TO 220 ON Semiconduci MBR20100CTG Ye Ye S S S Ye Yes Yes es Yes Ye Yes Yes es Yes Yes S SOD 123 ON Semiconduc MMSZ5247BT1G SOD 123 MMSZ5264BT1G or or or SOD 123 ON Semiconductor MMSD4148T1G i or or SOD 123 ON Semiconduc MMSZ5234BT1G ON Semiconduci 1N4007G Aavid Thermalloy 531002B02500G Re A
7. NCP1351PRINTGEVB NCP1351 16 V 32 V 40 W Printer Power Supply Evaluation Board User s Manual Description The present document describes a printer power supply operated by the NCP1351 a fixed f variable off time controller The board can deliver 10 W average on a 16 V output and 30 W average on a 32 V output with a transient peak power capability of 80 W It however exhibits a low standby power below 150 mW at no load whatever the input voltage Let us first review the benefit of using the NCP1351 The NCP1351 at a Glance Fixed ton Variable tor Current mode Control Implementing a fixed peak current mode control hence the more appropriate term quasi fixed ton the NCP1351 modulates the off time duration according to the output power demand In high power conditions the switching frequency increases until a maximum is hit This upper limit depends on an external capacitor selected by the designer In light load conditions the off time expands and the NCP1351 operates at a lower frequency As the frequency reduces the contribution of all frequency dependent losses accordingly goes down driver current drain capacitive losses switching losses naturally improving the efficiency at various load levels Peak Current Compression at Light Loads Reducing the frequency will certainly force the converter to operate into the audible region To prevent the transformer mechanical resonance the NCP1351 gradually reduces
8. avid Thermalloy 577202B00000G Micro Commercial Co DB105 BP SOIC 8 ON Semiconductor NCP1351CDR2G CEL NEC PS2501 1 H A TO 92 ON Semiconductor TL431CLPG iii a ttp onsemi com 8 NCP1351PRINTGEVB Table 4 BILL OF MATERIAL FOR THE NCP1351 40 W PRINTER EVALUATION BOARD continued owner omroton win mamma root semumewer Partin Awe He Designator Qty Description Value Tolerance Part Number Allowed Free OO p Rs Ri9 2 SMDResistor 2 7 k 0 25W 5 SOD 1206 CRCW12062R70JNEA R9 R12 2 SMD Resistor 0 Q 0 25 W 5 SOD 1206 CRCW12060000Z0EA 1 pa sw rescw oasonsw jw some si mlew fwewjmwjm Eh TEST PROCEDURE NCP1351PRINTER C TLS c u 4 i N a strap xe strap je semiconductor Cl Ji AC Input 85 265 Vac 16 V Output OV 32 V Output Figure 12 Test Procedure Schematic WARNING Be careful when manipulating the boards in operation lethal voltages up to 600 V are present on the primary side An isolation transformer is also recommended for safer manipulations Necessary Equipment Test Procedure e 1 current limited 230 Vrms AC source current limited 1 Apply 110 Vac on the Vin pins Output pins are to avoid board destruction in case of a defective part left floating e 1 DC volt meter able to measure up to 50 V DC 2 Measure the output voltage between pins 16 V et GND and between 32 V and GND with a volt meter
9. ctified unfiltered haversine This configuration allows for a quick release time after the controller is latched a direct connection to the AC line would also work Despite a small value for C3 the Vcc still maintains in no load conditions thanks to the split configuration HV rail Figure 3 The split Vcc configuration helps to start up in a small period of time C3 to charge alone but the addition of a second larger capacitor C7 ensures enough Vcc in standby The primary side feedback current is fixed to roughly 300 u A via Rg and an additional bias is provided for the TL431 1 mA at least must flow in the TL431 in worse case conditions full load Failure to respect this will degrade the power supply output impedance and regulation will suffer A 2 7 KQ value for Rig has proven to do just well without degrading the standby power The overvoltage protection uses a 17 V zener diode Do connected to the auxiliary Voc When the voltage on this rail exceeds 17 V plus the NCP1351 5 V latch trip point total is thus 22 V the circuit latches off and immediately pulls the Vcc pin down to 6 V The reset occurs when the injected current into the Vcc pin falls below a few uA that is to say when the power supply is disconnected from the mains outlet To speed up this reset phase a connection to the fully rectified haversine resets the system faster Figure 3 To satisfy the maximum power limit we don t need to add a true Over Po
10. e unique features of NCP1351C allow using a 100 uF bulk capacitor while delivering the transient peak power and ensuring the output is still regulated during line drop outs Finally the clamping network maintains the drain voltage below 520 V at high line 375 Vdc which provides 85 derating for the 600 V BVdss device Measurements Once assembled the board has been operated during 15 min at full power to allow some warm up time We used a WT210A from Yokogawa to perform all power related measurements coupled to an electronic ac source Table 1 EFFICIENCY 5 3 swf en ex Table 2 NO LOAD POWER Vin Pout 120 Vac 230 Vac En 5W 2W 83 4 79 5 1W Overpower Protection Level The power supply is able to deliver a peak power of 85 W during 500 ms from 85 Vac to 270 Vac It can deliver a constant output power of more than 40 W but less than 80 W over the same input voltage range Table 3 START UP TIME In the above tables we can see the excellent efficiency especially at light load conditions thanks to the natural frequency foldback of the NCP1351 The no load standby power stays below 150 mW at high line a good performance for a dual output power supply able to deliver 80 W Please note that the high voltage probe observing the drain was removed and the load totally disconnected to avoid leakage Despite operation in the audible range we did not notice any noise problems coming from either the transformer or
11. on the 50 V range The measurements should be respectively 16 and 32 volts 10 2 programmable electronic loads hitp onsemi com 9 NCP1351PRINTGEVB 3 Connect an electronic load between pins 32 V and GND and set up a current of 1 A Connect another electronic load between pins 16 V and GND and set up a current of 0 625 A Measure the output voltages that should be respectively 16 and 32 volts 10 Change the voltage applied on the Vin pins to 230 Vac Measure the output voltages that should again be respectively 16 and 32 volts 1090 Change the current setpoint for the electronic load The power supplv should go to short circuit protection Measure the output voltages that should be 0 V Change the current setpoint for the electronic load connected between pins 432 V and GND back to 1 A Turn off the AC voltage source Wait 5 seconds Apply it again the outputs should rise again Measure the output voltages that should again be respectively 16 and 32 volts 10 If every step has gone well the board is connected between pins 32 V and GND to 2 8 A considered to be ok Microsoft Excel is a registered trademark of Microsoft Corporation ON Semiconductor and are registered trademarks of Semiconductor Components 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 co
12. the RCD clamp capacitor 120 100 Vin min Visitas 80 60 A CCM Transition LL 40 20 0 20 40 60 80 Pout Figure 5 Switching Freq Variations vs Output Load 100 120 140 hitp onsemi com 4 NCP1351PRINTGEVB Scope Shots Below are some oscilloscope shots gathered on the evaluation board T TIT Tek Stopped Single Seq 13 Oct 06 15 27 23 a JJS JAN 4 TTT T L ial ie T Sa yas TTT i ji TIT Epe E Sa E ji T See l ae Sees e JI m Ch1 1004 Ch4 10 04 1 Li Li fta ET L L l l i n Chi 1007 4 0 4 Chi 100v Figure 7 Maximum Output Power Viy 265 Vac Conclusion The printer power supply built with the NCP1351 exhibits The limited number of surrounding components around an excellent performance on several parameters like the the controller associated to useful features timer based efficiency and the low load standby The transient switching protection latch input makes the NCP1351 an excellent frequency increase allows to deliver peak power during a choice for cost sensitive printer adapter designs limited time but if the overpower lasts longer than the set fault timer the controller safely latches off hitp onsemi com 5 NCP1351PRINTGEVB PCB LAYOUT NCP13S51PRINTER C TLS c stra ra KON t101
13. verage 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 subsidiaries affiliates and distributors harmless against all claims costs damages
14. wer Protection OPP circuit since our NCP1351C transiently authorizes higher power but safely latches off if the overpower lasts too long To ensure a fault timer duration of at least 500 ms to be able to deliver the 62 W power peak during 400 ms the timer capacitor C10 must be 1 5 uF This value will be adjusted depending on the specification according to the maximum peak power duration the adapter must sustain If anyway a constant overpower protection is needed over the whole input voltage range a simple arrangement can be used given the negative sensing technique we can use a portion of the auxiliary signal during the on time as it also swings negative However we don t want this compensation for short Ton durations since standby power can be affected For this reason we can insert a small integrator made of Co R26 see Figure 4 To avoid charging Co during the flyback stroke D14 clamps the positive excursion and offers a stronger negative voltage during the on time hitp onsemi com 3 NCP1351PRINTGEVB Rcomp 470 k OPP Adjust D14 1N4148 Rsense R26 N Vin Vaux Figure 4 A Simple Arrangement Provides an Adjustable Overpower Power Compensation A simple resistor connected between the auxiliary winding that swings negative during the ON time and the CT capacitor ensure a stable operation in CCM despite the duty cycle above 50 at very low line due to the ripple on the bulk capacitor Th
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