The AP3127 is a current mode PWM controller which is optimized for high performance, low standby power and cost effective offline flyback converters. The AP3127 coordinating with Diodes’ secondary side controller AP4320 and protocol decoding IC AP4370 provide a Flyback charger/adapter solution compatible to Qualcomm Quick Charge 2.0 protocol.
The PWM switching frequency at normal operation is internally fixed (about 65kHz for AP3127). 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 function is built-in to reduce EMI emission.
Internal slope compensation allows more stable Peak-Current Mode control over wide range of input voltage and load conditions. Internal line compensation ensures constant output power limit over entire universal line voltage range.
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. AP3127 combines secondary side OVP (SOVP) and UVP.