Sub-threshold value MOS (metal oxide semiconductor) tube-based overheat protection circuit

Abstract

The invention provides a sub-threshold value MOS (metal oxide semiconductor) tube-based overheat protection circuit which comprises a temperature detecting circuit, a voltage comparer and an output shaping circuit, wherein the temperature detecting circuit is in output connection with the voltage comparer, the voltage comparer is in output connection with the output shaping circuit, the output shaping circuit is in feedback connection with the temperature detecting circuit, and the output shaping circuit generates an output voltage for controlling follow-up circuits. The temperature detecting circuit consists of an MOS image current source of a sub-threshold value region and a resistance network, and the voltage comparer adopts a push-pull type two-stage voltage comparer. An audion is not used in the circuit, so that the accuracy of the temperature detecting circuit can be improved; and therefore, the overheat protection circuit is suitable for the common CMOS (complementary metal-oxide-semiconductor transistor) technology.

Description

technical field [0001] The invention relates to an over-temperature protection circuit in a power integrated circuit and an analog integrated circuit, in particular to an over-temperature protection circuit based on a sub-threshold MOS tube, which belongs to the technical field of microelectronics. Background technique [0002] The power consumption of integrated circuit chips such as power supply and driving devices is often very large, and the power consumption of switching power supply chips will be even greater due to the integration of high-voltage and high-current power switch tubes. The increase in power consumption increases the temperature of the chip. If the heat dissipation is not effective and the over-temperature protection circuit is unreliable, it is easy to cause thermal breakdown of the device, resulting in permanent damage to the device and possibly burning the chip. [0003] The general over-temperature protection circuit scheme is to use the conduction vo...

AI Technical Summary

Problems solved by technology

[0004] In order to solve the problem of the over-temperature point offset caused by the process deviation of the traditional over-temperature protection circuit, the present invention provides an over-temperature protection circuit based on the temperature characteristics of the MOS tube in the sub-threshold region. It does not use a triode and improves the temperature protection circuit. precision, and is suitable for common CMOS process

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