Current-limiting protection circuit

Abstract

The invention is closes a current-limiting protection circuit. The current-limiting protection circuit comprises an overcurrent detection module, a power driving module and a switching control module, wherein when the value of current in a driving signal sub-circuit is higher than an overcurrent value, a fourth triode and an MOS tube form dynamic balance of cascaded negative feedback, so that the MOS tube works in a constant current region and constant current is output, and constant driving power is provided for a load; and an overcurrent signal is output through the overcurrent detection module. According to the current-limiting protection circuit, the current overcurrent value can be rapidly adjusted according to different load requirements, and a condition that the circuit reliability is reduced as the current in the driving signal sub-circuit of a driving power supply is too high, is prevented, so that the technical effects of enhancing the stability and the reliability of a driving circuit is realized, and the current-limiting protection circuit is simple and practical. A triode and MOS tube cascading form is adopted, and the dynamic balance between the triode and the MOS tube is formed through the closed loop negative feedback when the overcurrent occurs, so that the MOS tube works in the constant current region, and the overcurrent signal and the constant current are output; and the constant driving power is provided for the load to keep the capability of the driving circuit, and certain on-line maintaining time can be provided.

Description

technical field [0001] The invention relates to a current limiting protection circuit, belonging to the technical field of circuits. Background technique [0002] With the rapid development of integrated circuit technology, the power consumption of power products and power drive circuits continues to increase, especially when the output is overloaded or even short-circuited, the large current on the power tube will permanently damage the circuit chip and electronic products. In order to avoid this situation, an overcurrent protection circuit is usually added to the chip. In the power drive circuit, the over-current protection circuit can be roughly divided into shutdown mode and current-limiting mode according to different control modes. The current-limiting mode is widely used because of its current drooping characteristics, and the circuit system can automatically resume work after the fault is eliminated. application. However, most of the current limiting protection cir...

AI Technical Summary

Problems solved by technology

However, most of the current limiting protection circuits will derate the output when the current is overloaded, which cannot provide stable driving power for the load, and the practicability is poor in some special occasions.

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