WCH CH224K Fast-Charging Protocol Chip: Function Changed but Model Number Remains Unchanged?
WCH’s CH224K datasheet revision (V1F to V2.1) removed single-resistor voltage configuration, disallowing floating CFG pins for 20V requests. This silently breaks existing designs relying on that method. WCH now recommends CH224A, which supports single-resistor mode but requires a 120kΩ resistor for 20V, complicating direct replacement without extra pads. The article questions whether such functional changes warrant a new model number.
Open-Source Smart Electronic Load Based on CH32V307, Embedded Competition Project Open Source
An open-source smart electronic load based on the CH32V307VCT6 microcontroller is presented, developed as a national second-prize entry in the 2023 embedded design competition. It supports constant current, voltage, resistance, and power modes, with 100V/10A/200W ratings. Schematics, PCB files, source code, and reports are freely available for learning and reference.