Current feedback type precise over-temperature protection circuit

Abstract

The invention discloses a current feedback type precise over-temperature protection circuit. The circuit comprises an operational amplifier OP, a first resistor R0, a second resistor R1, a first NMOS tube N0, a second NMOS tube N1, a first PMOS tube P0, a second PMOS tube P1, a third PMOS tube P2, a fourth PMOS tube P3, a first NPN audion Q0, a second NPN audion Q1, a comparator COMP, a first phase inverter, a second phase inverter and a third phase inverter. According to the current feedback type precise over-temperature protection circuit, the voltage of a negative temperature coefficient device is compared with the reference voltage, over-temperature signals are output, and temperature coefficient depending devices can be reduced, that is, the effect of the temperature influence factor and process is lowered; by adjusting the proportion of the same type of resistors, more precise adjustment of thermal shutdown temperature is achieved; a current feedback mode is used, the mirror image MOS width to length ratio is adjusted, and accordingly the temperature hysteresis quantity can be adjusted more precisely.

Description

technical field [0001] The invention relates to the field of electronic technology, in particular to a current feedback precise over-temperature protection circuit applied to a wireless charging control chip. 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 v...

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Problems solved by technology

[0003] The traditional over-temperature protection circuit is generally implemented by a voltage comparator. By comparing the voltage of the positive and negative temperature coefficient devices, the over-temperature signal is output, and the temperature hysteresis is adjusted by feedback to adjust the voltage drop of the resistor. This over-temperature protection circuit, At the same time, affected by positive and negative temperature coefficient devices, there are many influencing factors, and it is greatly affected by the process, so it is not easy to adjust the accurate thermal shutdown temperature and temperature hysteresis

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