The AP39303 is a highly integrated power switcher with a built-in Quasi-Resonant (QR) PWM controller and a 700V high performance power MOSFET. AP39303 is specially designed for offline power supply that requires ultra-low standby power, high-power density and comprehensive protection. Coordinating with secondary side USBPD or quick charger controller to provide a Flyback charger solution.
At no load or light load, the IC will enter the burst mode to minimize standby power consumption. The minimum switching frequency (typical: 24kHz) is set to avoid the audible noise. When the load increases, the IC will enter QR mode with frequency foldback to improve system efficiency and EMI performance. The maximum switching frequency (typical: 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.
The AP39303 provides an inner high-voltage start-up function through HV pin which can reduce the standby loss. Moreover, The AP39303 integrates a VCC LDO circuitry, allowing the LDO to regulate the wide range VCC_IN to an acceptable value. This makes the AP39303 to be a good choice in wide range output voltage application.
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, VCC Over Voltage Protection (VOVP), Secondary-side Output OVP (SOVP) and UVP (SUVP), internal OTP, Over Load Protection (OLP) and pins’ fault protection.
Combined with Diodes Incorporated’s synchronous controller APR347, AP39303 system can achieve the higher power conversion efficiency and the better thermal performance.
Switching AC-DC Adapter/Charger
ATX/BTX Auxiliary Power
Set-Top Box (STB) Power Supply
Open Frame Switching Power Supply
Quasi-Resonant Operation under all Line and Load Condition
Peak Current Mode Control @ DCM
Built-In 700V High Performance Power MOSFET
Embedded VCC LDO to Guarantee Wide Range VCC_IN Voltage
Low VCC Charge Current Reduces Standby Power in Output Short Situation