Fast charging protocol simulator based on CH224K

This chip can be used normally with a DIP switch, but because I have made similar things before, I forgot to turn the DIP switch back after use. As a result, the next time I connected a 5V device, it directly output 12V, and the board instantly malfunctioned. Smoked out, so I decided to make a version like this.

This module is based on CH224K and driven by STM8S003F3P6, realizing the functions of switching voltage and switching output with a single button. And the input voltage can be collected through the ADC, and the flashing frequency of the indicator light can be used to show whether the actual output voltage is the set voltage.

Because CH224K supports up to 20V charging protocol, this causes the Vgs to be up to 20V when using PMOS tubes as switches. The Vgs withstand voltage of small-volume MOS tubes is usually only 12V or 20V. It is difficult to choose small-volume and high-current MOS tubes. This module finally chose an NMOS tube with a voltage resistance of 30V, so that Vgs is only 3.3V. The MOS tube package is PDFN3333. As long as it is a 3x3 size MOS tube, the pin definitions are basically the same. If you are not sure whether it can be used, you can compare the package on the specification sheet.

https://www.bilibili.com/video/BV1w3411x7UA