NCP1217, NCP1217A PWM Controller, Fixed Frequency, Current Mode Housed in an SO8 or PDIP7 package, the NCP1217 represents the enhanced version of the NCP1203based controllers. Due to its high drive capability, NCP1217 drives large gatecharge MOSFETs, which www.onsemi.com together with internal ramp compensation and built in overvoltage protection, ease the design of modern AC/DC adapters. NCP1217 offers a true alternative to UC384Xbased designs. With an internal structure operating at different fixed frequencies MARKING (65100133 kHz), the controller features a highvoltage startup FET, DIAGRAMS which ensures a clean and loss less startup sequence. Its currentmode 8 control topology provides an excellent input audiosusceptibility and SOIC8 XXXXX inherent pulsebypulse control. Internal ramp compensation easily D SUFFIX ALYW 8 prevents subharmonic oscillations from taking place in continuous CASE 751 conduction mode designs. 1 1 When the current setpoint falls below a given value, e.g. the output power demand diminishes, the IC automatically enters the socalled skip cycle mode and provides excellent efficiency at light loads. Because this occurs at a user adjustable low peak current, no acoustic PDIP7 XXXXXXXXX noise takes place. P SUFFIX AWL The NCP1217 features two efficient protective circuitries: 1) In CASE 626B YYWWG presence of an overcurrent condition, the output pulses are disabled and 8 1 the device enters a safe burst mode, trying to restart. Once the default 1 has gone, the device autorecovers. 2) If an external signal (e.g. a temperature sensor) pulls Pin 1 above 3.2 V, output pulses are XXXXXX = Specific Device Code immediately stopped and the NCP1217 stays latched in this position. A = Assembly Location Reset occurs when the V collapses to ground, e.g. the user unplugs L, WL = Wafer Lot CC the power supply. Y, YY = Year W, WW = Work Week or G = PbFree Package Features CurrentMode with Adjustable SkipCycle Capability Builtin Internal Ramp Compensation DEVICE MARKING INFORMATION See detailed device marking information in the ordering AutoRecovery Internal Output ShortCircuit Protection information section on page 17 of this data sheet. Internal 1.0 ms SoftStart (NCP1217A Only) Limited DutyCycle to 50% (NCP1217A Only) Full Latchoff if Adjustment Pin is Brought High PIN CONNECTIONS Extremely Low NoLoad Standby Power Adj18 HV Internal Temperature Shutdown FB 2 7 NC 500 mA Peak Current Capability CS 3 6 V CC Fixed Frequency Versions at 65 kHz, 100 kHz and 133 kHz GND 4 5 Drv Direct Optocoupler Connection Internal Leading Edge Blanking (Top View) SPICE Models Available for TRANsient and AC Analysis These are PbFree Devices ORDERING INFORMATION See detailed ordering and shipping information in the ordering Typical Applications information section on page 17 of this data sheet. High Power AC/DC Converters for TVs, SetTop Boxes, etc. Offline Adapters for Notebooks Telecom DCDC Converters All Power Supplies Semiconductor Components Industries, LLC, 2015 1 Publication Order Number: April, 2015 Rev. 9 NCP1217/DNCP1217, NCP1217A See Application V OUT Section + Aux. + NCP1217 Adj HV 1 8 FB 2 7 CS V CC EMI 3 6 Gnd Drv FILTER 4 5 UNIVERSAL INPUT Ramp Adjustment + Figure 1. Typical Application Example PIN FUNCTION DESCRIPTION Pin No. Pin Name Function Description 1 Adj Adjust the skipping peak current This pin lets you adjust the level at which the cycle skipping process takes place. Shorting this pin to ground permanently disables the skip cycle feature. By bringing this pin above 3.1 V, you permanently shut off the device. 2 FB Sets the peak current setpoint By connecting an optocoupler to this pin, the peak current setpoint is ad- justed accordingly to the output power demand. 3 CS Current sense input This pin senses the primary current and routes it to the internal comparat- or via an L.E.B. By inserting a resistor in series with the pin, you control the amount of ramp compensation you need. 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 22 F. CC 7 NC This unconnected pin ensures adequate creepage distance. 8 HV Ensures a clean and lossless Connected to the highvoltage rail, this pin injects a constant current into startup sequence the V capacitor during the startup sequence. CC www.onsemi.com 2