安森美-1075-12V0.8A
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DN05018/DUniversal AC Input,12 V Output, 10 W E‐meterPower SupplyTable 1. DEVICE DETAILSDevice Application Input Voltage Output Power Topology I/O IsolationNCP1075, NCP431Smart Meters,Electric Meters,White Goods85 to 300Vac 5 to 10W Flyback Isolated(3kV)Characteristic Output SpecificationOutput Voltage12VdcRipple150mV p/p @ Full Load Nominal Current800mAMax Current 1.0A MaximumMin Current ZeroPFC (Yes/No)No, (Pout < 25W)Efficiency77% per Energy Star Inrush Limiting/Fuse Inrush Resistor (R1) & FuseOperating Temp. Range0 to +50°CCooling Method/Supply Orientation ConvectionSignal Level Control NoneCircuit DescriptionThis design note describes a simple, low power (10W orless), 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.The featured power supply is a simple flyback topology utilizing ON Semiconductor’s new NCP1075 SOT−223 monolithic switcher. This Design Note provides the complete circuit schematic details and transformer design for a 12V, 800mA amp power supply. Other output voltages from 3.3Vdc up to 28Vdc 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 plus optocoupler feedback scheme provides for excellent line and load regulation along with high input-to-output isolation.Performance characteristics for efficiency, output ripple, and internal MOSFET drain switching characteristics are shown in the figures and plots below. Enhanced input transient protection (lightning, etc.) can be accomplished with the addition of an appropriate TVS device across C2. Key Features•Universal AC Input Range (85–300 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/orOver-current Conditions•Secondary Circuit Easily Configured for Different Output V oltages•Inherent Over-current, Over-voltage andOver-temperature ProtectionDESIGN NOTECIRCUIT SCHEMATICN o t1. 2. 3. 4. 5. 6. 7. U 2 i s V i s h a y S F H 6156A −4 o p t o c o u p l e r o r s i m i l a r .10 W N C P 1075 P o w e r S u p p l y w i t h U n i v e r s a l A C I n p u tA C I u t12 V Transformer DesignProject/Customer: ON Semiconductor − NCP1075 10W PSUPart Description: 10 W Flyback Transformer, 100kHz, 12V/0.8A Out Schematic ID: T1Core Type: EF16 (E16/8/5); 3C90 Material or SimilarCore Gap: Gap for 1.7 to 2mH Inductance across Primary (Pins 1 − 4)Inductance: 1.85mH ±5%Bobbin Type: 8 Pin Horizontal Mount for EF16 Primary (4 − 1)12V Secondary (7, 8 − 5, 6)Vcc/Boost (3 − 2)100 turns of #35HN over 2 layers evenly. Insulate with a layer of Mylar tape.10 turns of #24 triple insulated wire over one layer. Self leads to pins per drawing. Insulate with a layer of Mylar tape.10 turns of #35HN spiral wound over 1layer with 2mm end margins.Insulate with tape for 3kV.Hipot: 3kV from Vcc/primary to secondary.Turns/Material/Gauge/Insulation DataWinding #/Type Windings (in order):A 5 Vout version of this transformer is available on request.Varnish assemblyAverage efficiency for both 120Vac and 230Vac was 77%.Figure 1. Efficiency vs. Load CurvesStandby (No Load) Input Power120 Vac: 74 mW230 Vac: 107 mWFigure 2. Full Load Output Ripple @ 120 Vac InputFigure 3. MOSFET Drain Voltage (120 Vac Input, 12 V, 1 A Load on Output)Figure 4. MOSFET Drain Voltage (120 Vac Input, 12 V, 250 mA Output)dBuV NCP1075 Flyback 12V 800mAFigure 5. EMI ProfileBILL OF MATERIALS Table 2. BILL OF MATERIALS FOR 12Vout, 10W NCP1075 FLYBACKDesignator Qty Description Value Tolerance Footprint Manufacturer ManufacturerPart NumberSubstitutionAllowedD7(12Vout)1Schottky Diode2A, 60V SMB ON Semiconductor MBRS260T3No D7 (5Vout)1Schottky Diode3A, 40V SMB ON Semiconductor MBRS2040L NoD1, D2, D3,D44Diode − 60Hz1A, 800V SMA ON Semiconductor MRA4007No D51Diode − Fast Recov.1A, 600V Axial Lead ON Semiconductor1N4937No D61Signal Diode100mA, 100V SOD−123ON Semiconductor MMSD4148A NoU31Programmable Zener 2.5V SOIC8/SOT23ON Semiconductor NCP431A NoU21Optocoupler CTR >/= 0.54-pin Vishay or NEC SFH6156A−4 orPS2561L−1YesU11Switcher IC −NCP1075100kHz SOT223ON Semiconductor NCP1075ST100No C1, C22“X” Cap, Box Type100nF, X2LS= 15mm Rifa, Wima TBD Yes C81“Y1” Cap, Disc Type1nF, Y1LS=7.5mm Rifa, Wima TBD Yes C41Ceramic Cap, Disc1nF, 1kV5%LS=7.5mm Rifa, Wima TBD YesC71Ceramic Cap,Monolythic1nF, 50V10%1206AVX, Murata TBD YesC10, C11,C123Ceramic Cap,Monolythic100nF, 50V10%1206AVX, Murata TBD YesC31Electrolytic Cap22m F,400/450V 10%LS=7.5mm,D=16mmUCC, Panasonic TBD YesC61Electrolytic Cap 4.7m F, 50Vdc10%LS=2.5mm,D=6.3mmUCC, Panasonic TBD YesC51Electrolytic Cap22m F, 25V10%LS=2.5mm,D=6.3mmUCC, Panasonic TBD YesC9A, C9B2Electrolytic Cap1000m F, 16V10%LS=5mm,D=12.5mmUCC, Panasonic TBD YesR11Resistor, 3W, WireWound 4.7W, 3W10%LS=7.5mm,D=7mmOhmite, Dale TBD YesR31Resistor, 0.5W,Metal Film 68k W, 0.5W10%Axial Lead;LS=12.5mmOhmite, Dale TBD YesR2A, R2B2Resistor, 1/4W SMD 3.3M W5%SMD 1206AVX, Vishay, Dale TBD YesR51Resistor, 1/4W SMD10W5%SMD 1206AVX, Vishay, Dale TBD Yes R41Resistor, 1/4W SMD1k W5%SMD 1206AVX, Vishay, Dale TBD Yes R9, R102Resistor, 1/4W SMD10k W1%SMD 1206AVX, Vishay, Dale TBD Yes R71Resistor, 1/4W SMD1k W1%SMD 1206AVX, Vishay, Dale TBD Yes R6(12Vout)1Resistor, 1/4W SMD1k W1%SMD 1206AVX, Vishay, Dale TBD Yes R6 (5Vout)1Resistor, 1/4W SMD240W1%SMD 1206AVX, Vishay, Dale TBD YesR8(12Vout)1Resistor, 1/4W SMD39k W5%SMD 1206AVX, Vishay, Dale TBD Yes R8 (5Vout)1Resistor, 1/4W SMD10k W1%SMD 1206AVX, Vishay, Dale TBD YesF11Fuse, TR−5 Style 1.5A TR−5,LS=5mmMinifuse YesL1A/B2Inductor (EMI Choke)1mH, 500mA See WurthDrawing LS=5mm,D=8mm7447728102YesT1 (12Vout)1Transformer E20/10/6 Core See MagDrawingWurth Magnetics YesJ1, J22Screw Terminal LS = 0.2″DigiKey# 281−1435−ND Yes NOTE:Grey indicates part change with Vout change.REFERENCES[1]ON Semiconductor Data Sheet for NCP1251/D Controller in TSOP6 Package.[2]ON Semiconductor Design Notes DN05012/D ,DN05014/D , DN05017/D .[3]ON Semiconductor Application Note AND8489/DPUBLICATION ORDERING INFORMATIONON Semiconductor and the 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, trade secrets, and other intellectual property. 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