The AP4370 is a decoding IC compatible to Qualcomm High Voltage Dedicated Charging Port (HVDCP) Quick Charge (QC) 2.0 protocol. It decodes the different combinations of D+/D- signals, generated by the portable device, into the related configurations of V1/V2, which can be used to change either voltage reference or voltage feedback divider resister for the controller IC to make the further constant voltage/constant current control. The AP4370 has over voltage discharge feature to accelerate output voltage decline transition. The AP4370 automatically provides 5V output configuration for the connected portable device that is not compatible to Qualcomm QC 2.0 protocol.