over temperature protection circuit

Abstract

The invention discloses an over-temperature protection circuit, which comprises a constant current generation circuit, an output control circuit, and an output shaping circuit. The constant current generation circuit is used to provide a stable current bias for the over-temperature protection circuit; the output control circuit is used to adjust the temperature The signal is converted into an electrical signal, and the output of the over-temperature protection circuit is controlled; the output shaping circuit is used to shape the output signal of the output control circuit, and the first resistor and the M1 tube are used to detect and respond to the chip temperature in real time; the present invention The proposed over-temperature protection circuit has a simple structure, does not require any high-precision voltage comparator, uses a small number of components, and has high temperature control accuracy. It can generate a shutdown signal very accurately at the thermal shutdown temperature threshold point, which is convenient for debugging. It has a temperature hysteresis function, which prevents the thermal oscillation of the chip near the temperature threshold point, and is very suitable for use in chips such as power management or LED drivers.

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, and the power consumption of the chip is increasing. Some integrated circuits such as switching power supplies, drive circuits, etc. We often face the problem that the temperature of the chip rises too fast near the power tube. Excessive temperature 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, it is necessary to integrate an over-temperature protection circuit near the power tube of the chip. When the local temperature of the chip reaches a c...

AI Technical Summary

Problems solved by technology

[0006] In order to solve the disadvantages of the traditional over-temperature protection scheme that the circuit structure is relatively complicated, high-precision comparators are needed, and the layout area is relatively large, the present invention proposes a circuit structure that is simple and does not require any comparators and PTAT current circuits. Over-temperature protection circuit with temperature hysteresis

Images