AP3302

Description

The AP3302 is a Peak-Current control, Quasi-Resonant (QR) PWM controller which is optimized for high performance, low standby power and cost effective offline flyback converters.

At no load or light load, the IC will enter the burst mode to minimize standby power consumption. The minimum switching frequency (about 22kHz) is set to avoid the audible noise. When the load increases, the IC will enter valley lock QR mode with frequency foldback to improve system efficiency and EMI performance. The maximum switching frequency (about 120kHz) is set to clamp the QR frequency to reduce switching power loss. Furthermore, the frequency dithering function is built in to reduce EMI emission.

Internal piecewise linear line compensation ensures constant output power limit over entire universal line voltage range.

Comprehensive protection features are included, such as brown out protection, cycle-by-cycle current limit (OCP), VCC Over Voltage Protection (VOVP), Secondary-side Output OVP (SOVP) and UVP (SUVP), internal OTP, Over Load Protection (OLP) and pins’ fault protection.

Feature(s)

• Very Low Start-Up Current
• Quasi-Resonant Operation with Valley Lock under All Line and Load Condition
• Non-Audible-Noise Quasi-Resonant Control
• Soft Start During Startup Process
• Frequency Fold Back for High Average Efficiency
• Constant Over Current Protection
• Secondary Winding Short Protection with FOCP
• Frequency Dithering for Reducing EMI
• VCC Maintain Mode
• Useful Pin Fault Protection: SENSE Pin Floating
• FB/Opto-Coupler Open/Short
• Comprehensive System Protection Feature: 
• VCC Over Voltage Protection (VOVP)
• Over Load Protection (OLP)
• Brown Out Protection (BNO)
• Secondary Side OVP (SOVP) and UVP (SUVP)
• Mini Size Package of SOT26

Application(s)

• Switching AC-DC Adapter/Charger
• ATX/BTX Auxiliary Power
• Set -Top Box (STB) Power Supply
• Open Frame Switching Power Supply