An over-temperature protection circuit

Abstract

The invention discloses an over-temperature protection circuit, comprising: a constant current generating circuit, an output control circuit, an output shaping circuit, an NPN transistor Q0 is a control switch tube, and a hysteresis control tube M4 can be either an NMOS tube or a PMOS tube. , the temperature hysteresis can be achieved by introducing additional current after over-temperature, and the hysteresis temperature can be set by adjusting the width-to-length ratio of the M4 tube. The over-temperature protection circuit proposed by the present invention has a simple structure and does not require any high-precision voltage comparison The device has a small number of components and high output precision. It can accurately generate a shutdown signal at the thermal shutdown temperature threshold point, which is convenient for debugging, and has a temperature hysteresis function. The hysteresis temperature setting is flexible and prevents thermal oscillations. Suitable for use in chips such as power supplies and drive circuits.

Description

technical field [0001] The invention relates to an over-temperature protection circuit used in electronic circuits, which is suitable for the field of analog integrated circuits. Background technique [0002] With the continuous development of integrated circuit technology, the integration of integrated circuits is increasing, the number of components integrated on a single chip is increasing, the power consumption of the chip is increasing, and the local temperature of the chip is rising too fast and too high The temperature of the chip will seriously affect the performance and reliability of the chip, and even cause permanent damage to the chip. [0003] In order to avoid damage to the chip caused by excessive temperature, an over-temperature protection circuit is generally introduced into the chip. When the chip temperature reaches a certain value, the chip will stop working and the chip will cool down. [0004] figure 1 It is a traditional over-temperature protection c...

AI Technical Summary

Problems solved by technology

[0006] In order to solve the defects of traditional over-temperature protection schemes such as complex circuit structure, low output accuracy, hysteresis comparator and large layout area, the present invention proposes a circuit structure with simple circuit structure and no need for any comparator. Over-temperature protection circuit with hysteresis function

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