Integrated protection circuit, method of providing current-limiting and short-circuit protection and converter employing the same

摘要

A power converter (200) has a current sensor (130) that senses an output current of the converter and generates a proportional voltage, and a controller (160) having an overvoltage protection circuit associated therewith. The overvoltage protection circuit includes a voltage sense input (V_SENSE) coupled to an output of the converter and a first reference voltage input (V_OVP) . An integrated protection circuit for providing current-limiting and short-circuit protection includes an operational amplifier circuit (210), coupled between the current sensor (130) and the controller (160), that generates a voltage signal and causes the controller to limit a current supplied by the converter to the output when the proportional voltage exceeds a second reference voltage. The integrated protection circuit also includes a conductive path (225, 224, 220), coupled between the operational amplifier circuit and the overvoltage protection circuit, that provides a path to apply the voltage signal to the voltage sense input when the proportional voltage exceeds the second reference voltage. The overvoltage protection circuit causes the controller to disable the converter when a voltage sensed at the voltage sense input exceeds a first reference voltage by a specified value. The integrated protection circuit thereby provides current-limiting and short-circuit protection for the converter.