Circuit for actively performing short-circuit and motor controller

Abstract

A circuit for actively performing short-circuit and a motor controller are provided. The circuit includes an undervoltage detecting circuit, an emergency power supply, a reverse-flow preventing circuit, and a gate level selecting switch. The undervoltage detecting circuit is configured to detect a driving power supply signal outputted from the driving power supply and output, in a case that an amplitude of the driving power supply signal is lower than a first threshold, an emergency active short-circuit enable signal. In response to the emergency active short-circuit enable signal, the emergency power supply is enabled and the gate level selecting switch is controlled to switch from a first conduction path to a second conduction path, to transmit an emergency power supply signal outputted from the emergency power supply to a bridge arm via the second conduction path.