DN05049/D Design Note – DN05049/D Universal AC Input, 5 or 12 Volt Output, 15 to 24 Watt Power Supply Device Application Input Voltage Output Power Topology I/O Isolation NCP1076/77 NCP431 Smart Meters, Electric Meters, White Goods 85 to 270 Vac 15 to 25 W CCM Flyback Isolated ( 3 kV) Output Specification Output Voltage Ripple Nominal Current Max Current Min Current 5 Vdc or 12 Vdc 200 mV p/p @ full load 4A/1.75A Amps (5V/12V) 4.5/2.0 Amps zero PFC (Yes/No) Average Efficiency Inrush Limiting / Fuse Operating Temp. Range Cooling Method / Supply Orientation Signal Level Control No (Pout < 25W) 80% minimum typical at 50% load Inrush resistor (Optional - R1) & Fuse 0 to +50°C Convection None Circuit Description This design note describes a simple, low power (25W or less), universal AC input, constant voltage power supply intended for powering utility electric meters or similar industrial equipment or white goods where isolation from the AC mains is required and low cost and high efficiency is essential. programmable zener plus optocoupler feedback scheme provides for excellent line and load regulation along with high input-to-output isolation. Performance characteristics for efficiency, output ripple, internal MOSFET drain switching characteristics, and conducted EMI are shown in the figures and plots below. . The featured power supply is a simple CCM flyback topology utilizing ON Semiconductor’s new NCP1076/1077 series of monolithic switchers in an SOT-223 package. This Design Note provides the complete circuit schematic details and transformer design for 5V/4A and 12V/1.75A power supplies. Other output voltages from 3.3 Vdc up to 28 Vdc are easy to implement by modifying the values (or ratings) of a few of the secondary side output components and the flyback transformer’s secondary winding (T1). The simple input EMI filter is adequate to pass Level B for FCC conducted EMI compliance and the NCP431 August 2013, Rev. 0 Key Features Universal AC input range (85 – 270 Vac). Input filter (pi-network) for conducted EMI attenuation and input transient protection. Very low standby (no load) power consumption. Frequency foldback under light load and/or overcurrent conditions. Secondary circuit easily configured for different output voltage/current combinations. Inherent over-current, over-voltage and over temperature protection. www.onsemi.com 1 DN05049/D 12V Circuit Schematic 1 R12 5.6K J1 L1A F1 1.5A C1 AC Input T1 1 mH 0.1uF "X" R1 4.7 ohms 3W R2A C2 0.1uF "X" L1B 3.3M D1-D4 MRA4007 X4 C3 1 mH 5.6K 6 68K 1/2W 1nF 1kV 8 D5 22uF 400V U1 R2B 3.3M R13 R3 C4 4 Primary Ground Plane 1N4937 10 R11 C13 47 1nF D7 3 2 1 NCP1077 (65 kHz) C5 22uF 25V J2 C9A C9B + 5 R4 2.7K C7 1nF MMSD 103 R5 D6 C6 4.7uF 50V 10 C10 MBRS 3100 1 7 Secondary Ground Plane 9 12Vout _ 1000uF, 16V C8 1nF "Y1" NOTES: R6 1K R7 1. Crossed schematic lines are not connected. 2. R4 value dependent on aux winding turns. 3. R1 is optional inrush limiting resistor. 4. U1 tab (pin 4) and D7 should have heatsinking clad pours. 5. Heavy lines indicate recommended ground plane areas. 6. L1A/L1B are Wurth 7447728102 7. U2 is Vishay SFH6156A-4 optocoupler or similar. C11 0.1uF 50V 0.1uF 50V 4 3 U2 1 10K U3 2 R8 R10 C12 39K 21.5K 0.1 NCP431 R9 10K 20 Watt NCP1077 Power Supply with Universal AC Input (Rev 4) 12 V Transformer Design 12V/2.0A, 65 kHz Version (Wurth Electronics # 750313861 Rev 1) Core: E25/10/6 (812E250) Primary A: 55 turns of 0.25mm mag wire 12V Secondary: 22 turns of 0.6mm Triple Insulated Wire (11 TPL, 2 layers) Aux/Vcc: 22 turns of 0.15mm mag wire spiral wound over 1 layer Primary B: 55 turns of 0.25mm mag wire Primary Inductance (Pri A and B in series): 2 mH +/- 10% (gap in center leg) Leakage Inductance (12Vsec & Aux shorted): 30 uH max 1 © 2013 ON Semiconductor. Disclaimer: ON Semiconductor is providing this design note “AS IS” and does not assume any liability arising from its use; nor does ON Semiconductor convey any license to its or any third party’s intellectual property rights. This document is provided only to assist customers in evaluation of the referenced circuit implementation and the recipient assumes all liability and risk associated with its use, including, but not limited to, compliance with all regulatory standards. ON Semiconductor may change any of its products at any time, without notice. Design note created by Frank Cathell, e-mail: [email protected] August 2013, Rev. 0 www.onsemi.com 2 DN05049/D 5V Circuit Schematic R12 5.6K J1 L1A F1 1 mH 1.5A C1 AC Input T1 0.1uF "X" R1 4.7 ohms 3W R2A C2 0.1uF "X" L1B 3.3M D1-D4 MRA4007 X4 C3 1 mH 5.6K C4 6 1nF 1kV 8 D5 22uF 400V U1 R2B 3.3M R13 R3 68K 1/2W Primary Ground Plane 4 1N4937 NCP1077 (65 kHz) C5 22uF 25V C13 47 1nF D7 3 2 1 10 R11 J2 C9A C9B + 5 SB80W06T C10 R4 2.7K C7 1nF MMSD 103 R5 D6 C6 10 4.7uF 50V 1 7 Secondary Ground Plane 9 5Vout _ 2,200uF, 6.3VV C8 1nF "Y1" NOTES: R6 240 R7 1. Crossed schematic lines are not connected. 2. R4 value dependent on aux winding turns. 3. R1 is optional inrush limiting resistor. 4. U1 tab (pin 4) and D7 should have heatsinking clad pours. 5. Heavy lines indicate recommended ground plane areas. 6. L1A/L1B are Wurth 7447728102 7. U2 is Vishay SFH6156A-4 optocoupler or similar. C11 0.1uF 50V 0.1uF 50V 4 3 U2 1 10K U3 2 R8 R10 C12 10K 21.5K 0.1 NCP431 R9 10K 20 Watt NCP1077 Power Supply with Universal AC Input (Rev 4) 5 V Transformer Design 5V/4A, 65 kHz Version (Wurth Electronics # 750313860 Rev 01) Core: E25/10/6 (812E250) Primary A: 55 turns of 0.25mm mag wire 5V Secondary: 11 turns bifilar of 0.6mm Triple Insulated Wire (2 layers) Aux/Vcc: 25 turns of 0.15mm mag wire spiral wound over 1 layer Primary B: 55 turns of 0.25mm mag wire Primary Inductance (Pri A and B in series): 2 mH +/- 10% (gap in center leg) Leakage Inductance (5Vsec & Aux shorted): 40 uH max August 2013, Rev. 0 www.onsemi.com 3 DN05049/D Efficiency vs Load Curves Typical Standby (no load) Input Power 120 Vac: 230 Vac: 30 mW 64 mW August 2013, Rev. 0 www.onsemi.com 4 DN05049/D Full Load Output Ripple @ 120 Vac Input 12Vout 5Vout Note: The demo boards under test do not contain an output L/C ripple filter (see schematics above). The output ripple can be further reduced another half-order of magnitude if necessary by the addition of a 4.7 uH inductor followed by a 100 uF capacitor. August 2013, Rev. 0 www.onsemi.com 5 DN05049/D MOSFET Drain Voltage Full Load – 120Vac Input Light Load – 120 Vac Input August 2013, Rev. 0 www.onsemi.com 6 DN05049/D EMI Profile - Quasi-peak (blue) and Average (red) dBuV NCP1077 Flyback 120Vac input, 12Vout, 20 watt load 80 70 60 EN 55022; Class B Conducted, Quasi-Peak 50 40 EN 55022; Class B Conducted, Average Pk 30 20 Average 10 0 -10 -20 1 10 8/7/2013 12:21:37 PM August 2013, Rev. 0 (Start = 0.15, Stop = 30.00) MHz www.onsemi.com 7 DN05049/D Bill of Materials for 15W/20W NCP1076/1077 Flyback (Rev4) h 8/7/2013 Designator Qty D7 (12Vout) D7 (5Vout) D1, 2, 3, 4 D5 D6 U3 U2 U1 1 1 4 1 1 1 1 1 Description Value Schottky diode Schottky diode Diode - 60 Hz, Diode - fast recov Signal diode Programmable zener Optocoupler Switcher IC - NCP1077/1076 3A, 100V 8A, 60V 1A, 800V 1A, 600V 100mA, 250V 2.5V CTR >/= 0.5 65 kHz Tolerance Footprint Manufacturer Manufacturer Part Number SMC DPak SMA axial lead SOD-123 SOIC8 / SOT23 4-pin SOT223 ON Semi ON Semi ON Semi ON Semi ON Semi ON Semi Vishay or NEC ON Semi MBRS3100 SB80W06T or MBRD660CT MRA4007 1N4937 MMSD103 NCP431A Digikey P/N = PS2561BL-1 NCP1077ST65 C1, C2 2 "X" cap, box type 100nF, X2 LS = 15 mm Rifa, Wima C8 1 "Y1" cap, disc type 1nF, Y1 LS = 7.5 mm Rifa, Wima C4 C7, C13 C10, 11, 12 C3 C6 C5 C9A,B (12V) C9A,B (5V) 1 2 3 1 1 1 2 2 Ceramic cap, disc Ceramic cap, monolythic Ceramic cap, monolythic Electrolytic cap Electrolytic cap Electrolytic cap Electrolytic cap Electrolytic cap 1 nF, 1kV 1 nF, 100V 100nF, 50V 22uF, 400/450V 4.7uF, 50Vdc 22uF, 25V 1000uF, 16V 2200 or 3300uF, 6.3V 5% 10% 10% 10% 10% 10% 10% 10% LS = 7.5 mm 1206 1206 LS=7.5mm, D=16mm LS=2.5 mm, D=6.3mm LS=2.5mm, D=6.3mm LS=5mm, D=12.5mm LS=5mm, D=12.5mm Rifa, Wima AVX, Murata AVX, Murata UCC, Panasonic UCC, Panasonic UCC, Panasonic UCC, Panasonic UCC, Panasonic Digi-Key P/N = 399-5426-ND Digikey P/N = BC2374-ND, Mouser P/N = 75-WKP102MCPEJ0KR Digi-Key P/N = 478-4227-ND TBD Digi-Key P/N = 311-1179-1-ND Digikey P/N = P5877-ND Digi-Key P/N = 565-1105-ND Digi-Key P/N = 565-1056-ND Digi-Key P/N = 565-1664-ND TBD R1 R3 R2A,R2B R10 R11 R5 R4 R7, R9 R12, R13 R6 (12Vout) R6 (5Vout) R8 (12Vout) R8 (5Vout) 1 1 2 1 1 1 1 2 2 1 1 1 1 Resistor, 3W, Wire wound Resistor, 0.5W, metal film Resistor, 1/4W SMD Resistor, 1/4W SMD Resistor, 1/4W SMD Resistor, 1/4W SMD Resistor, 1/4W SMD Resistor, 1/4W SMD Resistor, 1/4W SMD Resistor, 1/4W SMD Resistor, 1/4W SMD Resistor, 1/4W SMD Resistor, 1/4W SMD Use jumper wire 68K, 0.5W 3.3 Meg 21.5K 47 ohms 10 ohms 2.7K 10K 5.62K 1K 240 ohms 38.3K 10K 10% 10% 1% 1% 1% 1% 1% 1% 1% 1% 1% 1% 1% LS=7.5mm, D=7mm Axial lead; LS=12.5mm SMD 1206 SMD 1206 SMD 1206 SMD 1206 SMD 1206 SMD 1206 SMD 1206 SMD 1206 SMD 1206 SMD 1206 SMD 1206 Ohmite, Dale Ohmite, Dale AVX, Vishay, Dale AVX, Vishay, Dale AVX, Vishay, Dale AVX, Vishay, Dale AVX, Vishay, Dale AVX, Vishay, Dale AVX, Vishay, Dale AVX, Vishay, Dale AVX, Vishay, Dale AVX, Vishay, Dale AVX, Vishay, Dale Digi-Key P/N = 4.7AECT-ND Mouser = 71-FP01/268K0G5605EK Digi-Key P/N = 541-3.30MFCT-ND Digi-Key P/N = 541-21.5KFCT-ND Digi-Key P/N = 541-47.0FCT-ND Digi-Key P/N = 541-10.0FCT-ND Digi-Key P/N = 541-2.70KFCT-ND Digi-Key P/N = 541-10.0KFCT-ND Digi-Key P/N = 541-5.62KFCT-ND Digi-Key P/N = 541-1.00KFCT-ND Digi-Key P/N = 541-240FCT-ND Digi-Key P/N = 541-38.3KFCT-ND Digi-Key P/N = 541-10.0KFCT-ND TR-5, LS=5mm See Wurth Drawing See Mag Drawing See Mag Drawing LS = 0.2" Minifuse LS=5mm, D=8mm Wurth Magnetics Wurth Magnetics DigiKey Digi-Key P/N = WK4253BK-ND 7447728102 750313861 Rev 1 750313860 Rev 1 # 281-1435-ND F1 1 Fuse, TR-5 style L1A/B 1 Inductor (EMI choke) T1 (12Vout) 1 Transformer T1 (5Vout) 1 Transformer J1, J2 2 Screw Terminal Blue indicates part change with Vout change August 2013, Rev. 0 1.5A 1 mH, 500 mA E25/10/6 core E25/10/6 core www.onsemi.com Substitution Lead Comments Allowed Free No No No No No No Yes No Yes Yes Yes Yes Yes Yes Yes Yes 12V version Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes 8 DN05049/D References ON Semiconductor data sheet for NCP1076/1077 monolithic switcher. ON Semiconductor Design Notes DN05018, DN05043, DN05048 ON Semiconductor Application Note AND8489/D ON Semiconductor Flyback Transformer Design Tool: (http://www.onsemi.com/PowerSolutions/supportDoc.do?type=tools&rpn=NCP1075) Disclaimer: ON Semiconductor is providing this design note “AS IS” and does not assume any liability arising from its use; nor does ON Semiconductor convey any license to its or any third party’s intellectual property rights. This document is provided only to assist customers in evaluation of the referenced circuit implementation and the recipient assumes all liability and risk associated with its use, including, but not limited to, compliance with all regulatory standards. ON Semiconductor may change any of its products at any time, without notice. Design note created by Frank Cathell, e-mail: [email protected] August 2013, Rev. 0 www.onsemi.com 9