Apparatus for selective shutdown of devices of an integrated circuit in response to thermal fault detection

Abstract

An integrated circuit including one or more power devices, and circuitry which reliably (and independently) shuts down each power device that is detected to be in an undesired operating condition (e.g., one or both of an overcurrent condition and an overvoltage condition) that causes a thermal fault, but which does not shut down any power device that is not in such undesired operating condition. In typical implementations in which the integrated circuit has multiple power devices and an overvoltage detection circuit for each power device, the integrated circuit includes a thermal fault detection circuit and logic circuitry which receives the output of the thermal fault detection circuit and each overvoltage detection circuit. The logic circuitry generates signals which shut down appropriate ones of the power devices in response to the thermal fault detection and overvoltage detection signals it receives. The integrated circuit also includes fail safe thermal shutdown circuitry which shuts down all power devices upon detecting a more severe thermal fault even when no overcurrent or overvoltage condition is detected. In some embodiments, when a thermal fault is detected, each power device that is in an overcurrent and/or overvoltage condition (but none of the power devices that is in neither an overcurrent nor an overvoltage condition) is shut down. All the power devices are shut down upon detection of a more severe thermal fault even when no overcurrent or overvoltage condition is detected.