Overcurrent protect device of USB equipment

The utility model relates to an overcurrent protect device of USB equipment, its variable load circuit of MCU control through current detection module makes its load increase gradually, and power supply voltage detection circuitry detects the power supply voltage of USB power supply ware, and when power supply voltage was less than voltage threshold, power supply voltage detection circuitry sent asignal to MCU, inforied its USB power supply ware to be about to the current -limiting protection, acquire the maximum output current of USB power supply ware behind the MCU received signal to according to the consumption of the back level module of this maximum output current control USB slave unit, the consumption of avoiding back level module exceedes the cut -off current of USB power supply ware. 本实用新型涉及种USB设备的过流保护装置，其通过电流检测模块的MCU控制可变负载电路使其负载逐渐增加，供电电压检测电路检测USB供电器的供电电压，当供电电压小于电压阈值时，供电电压检测电路向MCU发送信号，通知其USB供电器即将限流保护；MCU接收信号后获取USB供电器的最大输出电流，并根据该最大输出电流控制USB从设备的后级模块的功耗，避免后级模块的功耗超过USB供电器的限流值。