NCP1377, NCP1377B PWM Current-Mode Controller for Free-Running Quasi-Resonant Operation The NCP1377 combines a true current mode modulator and a demagnetization detector which ensures full borderline/critical www.onsemi.com Conduction Mode in any load/line conditions together with minimum drain voltage switching (QuasiResonant operation). Due to its inherent skip cycle capability, the controller enters burst mode MARKING DIAGRAMS as soon as the power demand falls below a predetermined level. As 8 8 8 this happens at low peak current, no audible noise can be heard. For 1377 1377B NCP1377, an internal 8.0 s timer prevents the freerun frequency to 1 ALYW ALYW exceed 100 kHz (therefore below the 150 kHz CISPR22 EMI SOIC8 starting limit), while the skip adjustment capability lets the user DR SUFFIX 1 1 CASE 751 select the frequency at which the burst foldback takes place. For NC1377B, the internal timer duration is reduced to 3.0 s to allow operation at higher frequencies (up to 300 kHz). 8 8 The transformer core reset detection is done through an auxiliary 377D1 1 winding which, brought via a dedicated pin, also enables fast ALYW SOIC7 Over Voltage Protection (OVP). Once an OVP has been detected, the D1 SUFFIX IC permanently latches off. The 1377 features a sampling time of 1 CASE 751U 4.5 s whereas it is 1.5 s for the B version. The NCP1377 also features an efficient protective circuitries which, in presence of an overcurrent condition, disables the output pulses and enters a safe burst mode, trying to restart. Once the default 1377P 1377BP has gone, the device autorecovers. Finally an internal 1.0 ms AWL AWL 8 SoftStart eliminates the traditional startup stress. YYWWG YYWWG 1 1 1 PDIP7 Features P SUFFIX FreeRunning Borderline/Critical Mode QuasiResonant Operation CASE 626B Latched Overvoltage Protection AutoRecovery ShortCircuit Protection Via UVLO Crossover A = Assembly Location L, WL = Wafer Lot External Latch Triggering, e.g. Via Overtemperature Signal Y, YY = Year CurrentMode with Adjustable Skip Cycle Capability W, WW = Work Week or G = PbFree Package Internal 1.0 ms SoftStart (Note: Microdot may be in either location) Internal Temperature Shutdown Internal Leading Edge Blanking PIN CONNECTIONS 500 mA Peak Current Source/Sink Capability Under Voltage Lockout Level of 12.5 V (On) and 7.5 V (Min) Dmg HV 1 8 Direct Optocoupler Connection FB 2 SPICE Models Available for TRANsient Analysis Internal Minimum T CS 3 OFF 6 V CC These Devices are PbFree, Halogen Free/BFR Free and are RoHS GND 4 5 Drv Compliant (Top View) Typical Applications ACDC Adapters for Notebooks, etc. ORDERING INFORMATION Offline Battery Chargers See detailed ordering and shipping information in the package dimensions section on page 14 of this data sheet. Consumer Electronics (DVD Players, SetTop Boxes, TVs, etc.) Auxiliary Power Supplies (USB, Appliances, TVs, etc.) Semiconductor Components Industries, LLC, 2015 1 Publication Order Number: October, 2015 Rev. 13 NCP1377/DNCP1377, NCP1377B R* 12 V 1 A + GND NCP1377 OVP and + Demag 1 8 Universal 2 7 Network 3 6 4 5 + *Please refer to the application information section. Y1 Type Figure 1. Typical Application Schematic PIN FUNCTION DESCRIPTION Pin Symbol Function Description 1 Demag Core reset detection and OVP The auxiliary FLYBACK signal ensures discontinuous operation and offers a fixed overvoltage detection level of 7.2 V. 2 FB Sets the peak current setpoint By connecting an optocoupler to this pin, the peak current setpoint is adjusted accordingly to the output power demand. By bringing this pin below the internal skip level, you shut off the device. 3 CS Current sense input and skip This pin senses the primary current and routes it to the internal comparator via an cycle level selection L.E.B. By inserting a resistor in series with the pin, you control the level at which the skip operation takes place. 4 GND The IC ground 5 Drv Driving pulses The drivers output to an external MOSFET. 6 V Supplies the IC This pin is connected to an external bulk capacitor of typically 10 F. CC 7 This unconnected pin ensures adequate creepage distance. NC 8 HV Highvoltage pin Connected to the highvoltage rail, this pin injects a constant current into the V CC bulk capacitor and ensures a clean lossless startup sequence. www.onsemi.com 2