Fault tolerant power supply incorporating intelligent gate driver-switch circuit to provide uninterrupted power

摘要

A fault tolerant power supply system includes at least one load switch configured to connect an input voltage to an output node of the load switch when the load switch is turned on and at least one power channel coupled to the load switch to receive the input voltage. The power channel is configured as a buck converter and includes at least a high-side power switch and a low-side power switch. The fault tolerant power supply system is configured to measure a current flowing through the low-side power switch, to determine that the current flowing through the low-side power switch has exceeded a current limit threshold, and to disable the low-side power switch and the load switch in response to the determination that the current flowing in the low-side power switch has exceeded the current limit threshold.

主权项

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:
one or more load switches, each 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 when the load switch is turned on and the load switch disconnecting the input voltage from the output node when the load switch is turned off; and a plurality of power channels, each power channel having an input terminal coupled to the output node of one of the load switches 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, the power channel and an output capacitor connected between the output voltage node and a ground potential 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, the current sense circuit being configured to generate a first output signal having a first state when the current flowing in the low-side power switch has a peak current value exceeding a current limit threshold, the first output signal being coupled to the driver circuit to disable the low-side power switch of the respective power channel in response to the first output signal has the first state, the first output signal further being coupled to the load switch associated with the respective power channel to turn off the load switch in response to the first output signal has the first state; and wherein each load switch comprises a main switch having an input terminal connected to the input node and an output terminal connected to the output node and a control terminal, a first driver driving the control terminal of the main switch, a switch control circuit controlling the first driver and being configured to turn on or off the main switch in response to control signals of the power supply system, and a rapid switch turn-off circuit configured to receive the first output signal and to drive the control terminal of the main switch, the rapid switch turn-off circuit being configured to pull-down on the control terminal of the main switch to turn off the main switch in response to the first output signal having the first state, thereby turning off the load switch in response to the first output signal having the first state.