Linear voltage regulator with short-circuit protection function

Abstract

The invention provides a linear voltage regulator with a short-circuit protection function. The linear voltage regulator with the short-circuit protection function comprises an adjustment transistor, an output voltage control circuit, a short-circuit judgment circuit, a short-circuit protection circuit and a current limiting circuit. During the normal working period of the linear voltage regulator, the output voltage control circuit controls the value of output voltages to be maintained to be the expected value of the output voltages. During the short-circuit period, the short-circuit protection circuit controls the adjustment transistor to be turned off intermittently, and currents flowing through the adjustment transistor in the short-circuit period are limited to be lower than the currents in the normal working period through the circuit limiting circuit. The power loss of the adjustment transistor in the short-circuit period is effectively reduced, and the phenomenon of overheating is avoided, so that a heat protection module in the system in which the linear voltage regulator is integrated cannot be triggered, and the normal work of the entire system can not be affected.

Description

technical field [0001] The invention relates to the field of power electronics, and more specifically, relates to a linear voltage regulator with short-circuit protection. Background technique [0002] Linear regulators (such as linear regulators, low dropout regulators, LDO for short) are widely used in power management and other application systems due to their advantages of low cost, low noise, and low quiescent current. In a power management chip integrated with a linear voltage regulator, since the linear voltage regulator has to provide a relatively large current, when the output is short-circuited, the output terminal of the linear voltage regulator is directly grounded, and the excessive current flows through the linear voltage regulator The adjustment tube may cause damage to the entire power management chip, so a short circuit protection circuit is usually required in the linear regulator to prevent damage to the linear regulator and the power management chip when ...

AI Technical Summary

Problems solved by technology

[0005] In view of this, the present invention provides a linear voltage regulator with short-circuit protection to solve the problem in the prior art that the normal operation of the system is easily affected due to the large short-circuit power consumption when realizing the short-circuit protection of the linear voltage regulator

Images