Multi-mode combined short-circuit protection circuit, and working method and application thereof

Abstract

The invention belongs to the technical field of short-circuit protection circuits, and discloses a multi-mode combined short-circuit protection circuit, and a working method thereof. The multi-mode combined short-circuit protection circuit specifically comprises a sampling circuit, a constant-current protection circuit, a hiccup protection circuit, a benchmark reference voltage circuit and a voltage division circuit; the constant-current protection circuit comprises an operational amplifier U1A, the hiccup protection circuit comprises an operational amplifier U1B, when the output of the switching power supply is short-circuited, constant-current protection is carried out firstly, then hiccup protection is carried out, a hiccup protection mode can be started when the set constant-current protection time is reached, a short-circuit fault continuously exists, and the protection circuit repeats a constant-current protection-hiccup protection working mode; and switching power supply short-circuit faults are eliminated, and normal functions are recovered. The short-circuit protection circuit has the characteristics of high capacity of constant-current protection and capacitive load and low short-circuit power consumption of hiccup protection, ensures that the hiccup protection can be performed when the constant-current protection reaches the designed time, solves the problem of high short-circuit power consumption of a high-power switching power supply, and has the advantage of high capacity of capacitive load.

Description

technical field [0001] The invention belongs to the technical field of short-circuit protection circuits, and in particular relates to a multi-mode combination short-circuit protection circuit and its working method and application. Background technique [0002] Switching power supplies continue to develop in the direction of high power, small size, high efficiency, and high reliability. With the advancement of high-efficiency technology, the power dissipation of switching power supplies has been effectively controlled, the volume size has been continuously reduced, and the power density has become higher and higher. However, the difficulty of short-circuit protection circuit design has continued to increase, which restricts the improvement of the reliability of switching power supplies. There are two commonly used short-circuit protection circuits at present, one is a constant current protection circuit, and the other is a hiccup protection circuit. [0003] (1) Constant c...

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Problems solved by technology

[0009] The purpose of the present invention is to provide a multi-mode combined short-circuit protection circuit and its working method and application, which solves the problem of large short-circuit power consumption of high-power switching power supplies, and has the advantage of strong capacitive load capacity

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