Over-temperature protection circuit used for power module

Abstract

The invention discloses an over-temperature protection circuit used for a power module. The circuit includes a detection module used for detecting the temperature of the power module so as to generate detection signals; an output response module connected with the detection module; a positive and negative thermal-feed hysteresis module which is connected with the output response module and the detection module and used for adjusting detection signals according to control signals so as to realize thermal hysteresis; and a protection module which is connected with the output response module and used for controlling the power module to stop work according to the control signals so as to realize protection of the power module. The output response module includes a first NMOS tube and a Zener diode, and a first node is arranged between the first NMOS tube and the Zener diode. The voltage of the first node changes according to the detection signals and the output response module outputs the control signals according to the voltage of the first node. The over-temperature protection circuit used for the power module is capable of detecting accurately the temperature of the power module and has a thermal hysteresis function and capable of effectively preventing happening of a thermal oscillation phenomenon.

Description

technical field [0001] The invention relates to the technical field of over-temperature protection circuits, in particular to an over-temperature protection circuit for power modules. Background technique [0002] The intelligent power module is an advanced hybrid integrated circuit that integrates power semiconductor devices, gate drive circuits, and protection circuits. It is widely used in various fields such as frequency conversion home appliances, inverter power supplies, and industrial electrical automation. Intelligent power modules are high-power semiconductor devices that generate high temperatures during operation. Therefore, they generally contain an over-temperature protection circuit to monitor the temperature inside the module in real time. When the temperature exceeds the standard, the over-temperature protection is activated. circuit to achieve the purpose of protecting the intelligent power module. [0003] The traditional over-temperature protection circui...

AI Technical Summary

Problems solved by technology

However, as the temperature of the intelligent power module drops, the PNP transistor Q1' will be cut off again, and V OUT At this time, the intelligent power module starts to work normally again, causing the temperature of the intelligent power module to rise again, and so on, causing the intelligent power module to undergo thermal oscillation near the over-temperature protection threshold point. This thermal oscillation is harmful to the intelligent The normal operation and reliability of the power module have a great influence

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