关键词: 过流保护, 电流检测, AD采样, MOSFET关断控制

Abstract: For DC power supply circuit, the common overcurrent protection measures, which have the preseted overload value, can’t be adjusted following the actual load current value. The overload protection circuit based on the current detect with the precision op amplifier, the AD sampling and operation of MCU processing unit, and the MOSFET shutdown control circuit is designed. The working principle of dynamically adjusting the overload current value and starting overload protection is analyzed. On the test circuit, the effectiveness and stability of the circuit are verified, indicating that the design achieves the expected results.

Key words: overcurrent protection, current sensing, AD sampling, MOSFET shutdown control