NCP1028 High-Voltage Switcher for Medium Power Offline SMPS Featuring Low Standby Power www.onsemi.com The NCP1028 offers a new solution targeting output power levels from a few watts up to 15 W in a universal mains flyback application. Our proprietary highvoltage technology lets us include a power MARKING MOSFET together with a startup current source, all directly DIAGRAM connected to the bulk capacitor. To prevent lethal runaway in low input voltage conditions, an adjustable brownout circuitry blocks the activity until sufficient input level is reached. 8LEAD PDIP P1028Pxxx Currentmode operation together with an adjustable ramp P SUFFIX AWL compensation offers superior performance in universal mains CASE 626A YYWWG applications. Furthermore, an Over Power Protection pin brings the ability to precisely compensate all internal delays in high input voltage conditions and optimize the maximum output current capability. xxx = 65 or 100 Protection wise, a timer detects an overload or a shortcircuit and A = Assembly Location stops all operations, ensuring a safe autorecovery, low duty cycle burst WL = Wafer Lot operation. YY = Year WW = Work Week Finally, a great R figure makes the circuit an excellent choice DS(on) G = PbFree Package for standby/auxiliary offline power supplies or applications requiring higher output power levels. Features PIN CONNECTIONS Builtin 700 V MOSFET with Typical R of 5.8 , T = 25C DS(on) J V CC GND CurrentMode Fixed Frequency Operation: 65 kHz and 100 kHz Fixed Peak Current of 800 mA Ramp Comp. OPP SkipCycle Operation at Low Peak Currents BrownOut Internal Current Source for Clean and Lossless Startup Sequence FB Drain AutoRecovery Output Short Circuit Protection with TimerBased Detection (Top View) Programmable BrownOut Input for Low Input Voltage Detection Programmable Over Power Protection Input to Permanently Latchoff the Part ORDERING INFORMATION Internal Frequency Jittering for Improved EMI Signature Extended Duty Cycle Operation to 80% Typical Device Package Shipping* NoLoad Input Standby Power of 85 mW 265 Vac NCP1028P065G PDIP8 50 Units / Rail 500 mW Loaded, Input Power of 715 mW 230 Vac (PbFree) These Devices are PbFree and are RoHS Compliant* NCP1028P100G PDIP8 50 Units / Rail (PbFree) Typical Applications *For additional information on our PbFree strategy Medium Power ACDC Adapters for Chargers and soldering details, please download the Auxiliary/Standby Power Supplies for ATX and TVS Power Supplies ON Semiconductor Soldering and Mounting Techniques Reference Manual, SOLDERRM/D. Reference 230 VAC 90265 VAC NCP1028 5.8 25 W* 15 W* *Typical values, openframe, 65 kHz version, R < 75C/W, T = 50C. JA A **For additional information on our PbFree strategy and soldering details, please download the ON Semiconductor Soldering and Mounting Techniques Reference Manual, SOLDERRM/D. Semiconductor Components Industries, LLC, 2015 1 Publication Order Number: January, 2015 Rev. 3 NCP1028/DNCP1028 V out + OPP* NCP1028 1 8 + 2 7 85265 VAC BO 3 5 4 + + GND Ramp Comp.* *Optional component Figure 1. Typical Application PIN FUNCTION DESCRIPTION Pin No. Symbol Function Description 1 V Powers the Internal This pin is connected to an external capacitor of typically 22 F. CC Circuitry 2 Ramp Comp. Ramp Compensation To extend the duty cycle operation in Continuous Conduction Mode (CCM), in CCM pin 3 offers the ability to inject ramp compensation in the controller. If unused, short this pin to V . CC 3 BrownOut BrownOut and By monitoring the bulk level via a resistive network, the circuit protects itself Latchoff Input from low mains conditions. If an external event brings this pin above 4.0 V, the part fully latches off. 4 FB Feedback Signal Input By connecting an optocoupler to this pin, the peak current setpoint is adjusted accordingly to the output power demand. 5 Drain Drain Connection The internal drain power switch circuit connection. This unconnected pin ensures adequate creepage distance. 7 OPP Over Power Protection Driving this pin reduces the power supply capability in high line conditions. If no Over Power Protection is needed, short this pin to ground. 8 GND The IC Ground www.onsemi.com 2