System for providing over-current protection for switching power converter

Abstract

The invention discloses a system for providing over-current protection for a switching power converter. The system comprises a front-edge blanking circuit, a linear compensation circuit and an over-current protection comparer, wherein the front-edge blanking circuit is configured to generate a front-edge blanking effect on a detection signal of a current which flows through an external switching tube of the switching power converter; the linear compensation circuit is configured for performing linear compensation on a threshold voltage of the over-current protection comparer; and the over-current protection comparer is configured for generating an over-current protection comparison signal. By a linear compensation over-current protection circuit, the time delay of a system internal over-current protection output signal is taken into consideration, so the permanent damage of a switching tube of a metal-oxide semiconductor field effect transistor (MOSFET) caused by large-current conduction which may be generated at a high input voltage is avoided; and a maximum output power is stabilized, so the maximum power planarization of a power system can be realized in a full-voltage input range.

Description

technical field [0001] The invention relates to the field of switching power supplies, more specifically, the invention provides an overcurrent protection system for switching power supply converters. Background technique [0002] As the power supply equipment of all electronic products, the power supply is not only designed to meet the performance requirements, but also its own protection measures are also very important. Such as over-current protection, over-voltage protection, over-temperature protection and so on. At present, in switching power converters, high-power MOSFET switching tubes with high-frequency switching characteristics have been widely used. However, its ability to withstand short-term overload is weak. Under abnormal conditions such as faults or short circuits in the load circuit system, the power consumption will increase sharply, which will affect the normal operation of the MOSFET switch tube and may cause permanent damage to the power supply system....

AI Technical Summary

Problems solved by technology

[0003] In the traditional overcurrent protection system, an RC filter needs to be connected to the current detection pin of the switching power supply converter, which will increase the number of components in the switching power supply system

At the same time, in the overcurrent protection, the delay of the internal signal of the converter is not considered, which will cause the current to increase for a short time, which increases the risk of permanent damage to the switch.

Images