High-precision overtemperature protecting circuit

Abstract

The invention discloses a high-precision overtemperature protecting circuit which comprises the components of a band gap reference circuit, a threshold generating circuit and a lag comparator output circuit, wherein the band gap reference circuit, the threshold generating circuit and the lag comparator output circuit are successively connected electrically. The band gap reference circuit is used for generating a reference voltage which is irrelevant with the temperature. The threshold generating circuit is used for generating two threshold voltages according to the reference voltage which is generated by the band gap reference circuit. The lag comparator output circuit selects one from two threshold voltages which are generated by the threshold generating circuit as a comparing value, and utilizes the summation of voltage differences between the base electrodes and the emitter electrodes of two NPN triodes as the other comparing value. The lag comparator output circuit determines whether overtemperature occurs through the comparison result between the two comparing values.

Description

technical field [0001] The invention relates to the field of electronic technology, in particular to a high-precision over-temperature protection circuit. Background technique [0002] With the continuous development of semiconductor integrated circuit technology and the progress of semiconductor technology, the integration level of integrated circuits is getting higher and higher, and the power consumption is also increasing, so that the local temperature of the chip is too high and the chip is greatly damaged. In order to protect the integrated circuit chip from high temperature damage, it is necessary to design a special over-temperature protection circuit. When the temperature exceeds a certain threshold, the over-temperature protection circuit outputs a shutdown signal, so that the chip partially or completely stops working. [0003] The traditional over-temperature protection circuit is generally implemented by a voltage comparator, and the thermal shutdown, thermal t...

AI Technical Summary

Problems solved by technology

This kind of over-temperature protection circuit is affected by resistance and positive and negative temperature coefficient devices at the same time. There are many influencing factors, and it is greatly affected by the process. It is not easy to adjust to an accurate thermal shutdown temperature, and it is impossible to achieve high-precision over-temperature protection.

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