Current limiting circuit and current limiting method

Abstract

The invention relates to a current limiting circuit and a current limiting method, and belongs to the field of integrated circuits, which can realize a fast and accurate current limiting function, andcan be implemented in a low voltage standard CMOS process and a high voltage BCD process. The current limiting circuit includes a load current sampling module for sampling a load current of a power switch tube, converting the sampled load current into a voltage, and inputting the converted voltage to a slow and precise current limiting module and a fast responding current limiting module; the slow and precise current limiting module configured to control a gate voltage of the power switch tube to limit the load current to a preset current limit threshold when the converted voltage is higher than a first reference voltage; and the fast responding current limiting module configured to control a gate voltage of the power switch tube to quickly respond and limit current to the load current when the converted voltage is higher than a second reference voltage, wherein the first reference voltage is less than the second reference voltage.

Description

technical field [0001] The present disclosure relates to the field of integrated circuits, and in particular, to a current limiting circuit and a current limiting method. Background technique [0002] The power distribution switching circuit with current limiting function can distribute power for devices such as tablets, multimedia players, Bluetooth speakers, and other devices, and provide current limiting protection for switching regulators. However, in the existing power distribution switch circuit with current limiting function, the current limiting response speed is very slow when the device is short-circuited instantaneously, so that there will be a large peak current at the moment of short-circuit, which may cause potential damage to the switching regulator. risk. Although the Chinese patent application with the publication number CN102769281A discloses a fast-response current-limiting protection circuit, it needs to add a charge pump circuit, which is not conducive ...

AI Technical Summary

Problems solved by technology

However, in the existing power distribution switch circuit with current limiting function, the current limiting response speed is very slow when the device is short-circuited instantaneously, so that there will be a large peak current at the moment of short-circuit, which may cause potential damage to the switching regulator. risk

Although the Chinese patent application whose publication number is CN102769281A discloses a fast response current limiting protection circuit, it needs to increase the charge pump circuit, which is not conducive to the realization in the low-voltage standard CMOS process.

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