Patent ID: 9705395
Date: 2017-07-11
CPC Classifications: H02H,H02M

Claim:
1. A fault tolerant power supply system, the power supply system receiving an input voltage and generating an output voltage on an output voltage node, the power supply system comprising: a load switch having an input node coupled to the input voltage and an output node, the load switch providing the input voltage on the output node in response to the load switch being turned on and the load switch disconnecting the input voltage from the output node in response to the load switch being turned off, the load switch comprising a main switch connected between the input node and the output node and controlled by a control terminal and a turn-off circuit configured to drive the control terminal of the main switch; a plurality of power channels, each power channel having an input terminal coupled to the output node of the load switch and an output terminal coupled to the output voltage node of the power supply system, each power channel comprising a driver circuit, a high-side power switch and a low-side power switch connected in series, and an output inductor; and an output capacitor connected between the output voltage node and a ground potential, each power channel and the output capacitor forming a buck converter, wherein each power channel of the plurality of power channels further comprises a current sense circuit to measure a current flowing in the low-side power switch of the respective power channel, the current sense circuit being configured to generate a first output signal having a first state in response to the current flowing in the low-side power switch having a peak current value exceeding a current limit threshold, the first output signal being coupled to the driver circuit of the respective power channel to disable the low-side power switch of that power channel in response to the first output signal having the first state, the first output signal further being coupled to the turn off circuit of the load switch to turn off the load switch in response to the first output signal having the first state.