Charging MOS transistors have advantages such as high input impedance, low power consumption, and easy integration, and are widely used in the field of high-frequency power supplies. Its working principle is simple and efficient, capable of accurately controlling the on/off of current, and suitable for charging management in various electronic devices. By controlling the gate voltage to regulate the on/off state of the current, functions such as charging, voltage conversion, and current control can be achieved. Its working principle is based on electric field control, and it has the characteristics of high efficiency and low power consumption. It is an important component in the charging management circuit.