A Product Line of Diodes Incorporated AP3125B GREEN MODE PWM CONTROLLER Description Pin Assignments The AP3125B is a current mode PWM controller which is optimized for high performance, low standby power and cost effective offline (Top View) flyback converters. The PWM switching frequency at normal operation is internally fixed Pin 1 Mark (about 65kHz). In middle load, the IC will enter green mode to improve system efficiency with the help of frequency foldback. A minimum switching frequency (about 20kHz) is set to avoid the audible noise. In no load or light load, the IC will enter the burst mode to minimize standby power. Furthermore, the frequency dithering GND GATE 6 1 function is built-in to reduce EMI emission. Internal slope compensation allows more stable Peak-Current Mode FB VCC 2 5 control over wide range of input voltage and load conditions. Internal line compensation ensures constant output power limit over entire universal line voltage range. SENSE BNO 3 4 Comprehensive protection features are included, such as cycle-by- cycle current limit (OCP), VCC Over Voltage Protection (VOVP), internal OTP, Over Load Protection (OLP) and pins fault protection. Built-in Brownout (BNO) and Line Over Voltage Protection (LOVP) SOT26 are also integrated in AP3125B. Features Applications Very Low Start-up Current Switching AC-DC Adapter/Charger Current Mode Control ATX/BTX Auxiliary Power Non-audible-noise Green-mode Control Set-top Box (STB) Power Supply Internal Slope Compensation Open Frame Switching Power Supply Soft Start During Startup Process Frequency Fold Back for High Average Efficiency Secondary Winding Short Protection with FOCP Soft Switching for Reducing EMI VCC Maintain Mode Brownout Protection (BNO) Line Over Voltage Protection (LOVP) Useful Pin Fault Protection: SENSE Pin Floating SENSE Pin Short to Ground FB/Opto-coupler Open/Short Comprehensive System Protection Feature: VCC Over Voltage Protection (VOVP) Over Load Protection (OLP) Mini Size with Packages Pin to Pin Compatible with AP3105NA/NV/NL/NR Totally Lead-free & Fully RoHS Compliant (Notes 1 & 2) Halogen and Antimony Free. Green Device (Note 3) Notes: 1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant. 2. See A Product Line of Diodes Incorporated AP3125B Typical Applications Circuit L2 T1 C6 R6 C5 R4 C2 R13 C8 C7 R5 R19 C4 R14 C3 NTC R8 R2 R3 VCC GATE R10 C1 R9 R15 BNO C10 SENSE R20 C11 R16 R11 R12 AP3125B R17 R7 VR1 C20 AZ431 C9 FB R18 GND Pin Descriptions Pin Number Pin Name Function 1 GND Signal ground. Current return for driver and control circuits 2 FB Feedback. Directly connected to the opto-coupler 3 BNO Control brownout protection 4 SENSE Current sense 5 VCC Supply voltage of driver and control circuits 6 GATE Gate driver output 2 of 12 AP3125B July 2014 Diodes Incorporated www.diodes.com Document number: DS36659 Rev. 3 - 2 NEW PRODUCT F1 + ~ ~ ~ -