NCP1250 PWM Controller, Current Mode, for Offline Power Supplies The NCP1250 is a highly integrated PWM controller capable of www.onsemi.com delivering a rugged and high performance offline power supply in a tiny TSOP6 or PDIP8 package. With a supply range up to 28 V, the MARKING controller hosts a jittered 65 kHz or 100 kHz switching circuitry DIAGRAMS operated in peak current mode control. When the power on the TSOP6 secondary side starts to decrease, the controller automatically folds (SOT236) back its switching frequency down to a minimum level of 26 kHz. As 25xAYW SN SUFFIX the power further goes down, the part enters skip cycle while limiting CASE 318G 1 the peak current. 1 Over Power Protection (OPP) is a difficult exercise especially when noload standby requirements drive the converter specifications. The ON proprietary integrated OPP lets you harness the maximum PDIP8 125xy65 delivered power without affecting your standby performance simply SUFFIX P AWL via two external resistors. An Over Voltage Protection input is also Case 626 YYWWG combined on the same pin and protects the whole circuitry in case of optocoupler failure or adverse open loop operation. Finally, a timerbased shortcircuit protection offers the best protection scheme, letting you precisely select the protection trip point 25x = Specific Device Code x = A, 2, C, D, 0, 1 irrespective of a loose coupling between the auxiliary and the power y = A or B windings. A = Assembly Location WL = Wafer Lot Features Y, YY = Year FixedFrequency 65 or 100 kHz CurrentMode Control Operation W, WW = Work Week Internal and Adjustable Over Power Protection (OPP) Circuit G or = PbFree Package Frequency Foldback Down to 26 kHz and SkipCycle in Light Load (Note: Microdot may be in either location) Conditions PIN CONNECTIONS Internal Ramp Compensation Internal Fixed 4 ms SoftStart GND 1 6 DRV 100 ms TimerBased AutoRecovery ShortCircuit Protection Frequency Jittering in Normal and Frequency Foldback Modes 2 5 FB V CC Option for AutoRecovery or Latched ShortCircuit Protection OPP/Latch 3 4 CS OVP Input for Improved Robustness Up to 28 V V Operation CC TSOP6 (Top View) +300 mA/500 mA Source/Sink Drive Capability Less than 100 mW Standby Power at High Line GND OPP/LATCH 1 8 EPS 2.0 Compliant These are PbFree Devices DRV N/C 2 7 N/C 3 6 FB Typical Applications acdc Converters for TVs, Settop Boxes and Printers V 4 5 CS CC Offline Adapters for Notebooks and Netbooks PDIP8 (Top View) ORDERING INFORMATION See detailed ordering and shipping information in the package dimensions section on page 3 of this data sheet. Semiconductor Components Industries, LLC, 2015 1 Publication Order Number: April, 2015 Rev. 10 NCP1250/DNCP1250 Vbulk Vout OVP OPP . NCP1250 1 6 2 5 3 4 ramp comp. Figure 1. Typical Application Example (TSOP6) PIN DESCRIPTION Pin N PDIP8 TSSOP6 Pin Name Function Pin Description 1 1 GND The controller ground. 6 2 FB Feedback pin Hooking an optocoupler collector to this pin will allow regulation. 8 3 OPP/OVP Adjust the Over Power Protection A resistive divider from the auxiliary winding to this Latches off the part pin sets the OPP compensation level. When brought above 3 V, the part is fully latched off. 5 4 CS Current sense + ramp This pin monitors the primary peak current but also compensation offers a means to introduce ramp compensation. 4 5 V Supplies the controller This pin is connected to an external auxiliary voltage CC and supplies the controller. 2 6 DRV Driver output The drivers output to an external MOSFET gate. OPTIONS Controller Frequency OCP Latched OCP AutoRecovery NCP1250ASN65T1G 65 kHz Yes No NCP1250BSN65T1G 65 kHz No Yes NCP1250ASN100T1G 100 kHz Yes No NCP1250BSN100T1G 100 kHz No Yes NCP1250BP65G 65 kHz No Yes www.onsemi.com 2