Over-temperature delay protection circuit with wide power voltage range

Abstract

The invention provides an over-temperature delay protection circuit with a wide power voltage range. The over-temperature delay protection circuit comprises a starting circuit module, an I<PTAT (proportional to absolute temperature)> current generating circuit module, a reference voltage module, an over-temperature detection module and a cascade inverter module. Output currents of the starting circuit module are provided to an input end of the I<PTAT> current generating circuit module, output voltages of the I<PTAT> current generating circuit module are provided to an input end of the reference voltage module and an input end V<1> of the over-temperature detection module, output voltages V<ref (reference)> of the reference voltage module are provided to an input end V<2> of the over-temperature detection module and an input end of the starting circuit module, and output voltages of the over-temperature detection module are provided to an input end of the cascade inverter module; output voltages V<3> of the cascade inverter module are provided to an input end V<4> of the over-temperature detection module. The over-temperature delay protection circuit has the advantages that I<PTAT> currents can be precisely mirrored by the reference voltage module and the over-temperature detection module, current errors between the reference voltage module and the over-temperature detection module can be reduced, accordingly, jumping temperatures are hardly shifted, and the power voltage input range can be expanded.

Description

technical field [0001] The invention relates to the technical field of integrated circuits, in particular to an over-temperature hysteresis protection circuit suitable for wide power supply voltage. Background technique [0002] Over-Temperature-Protection (OTP) circuit is an integral part of modern power management chips, and its characteristic is that if the circuit temperature exceeds the threshold T H , the circuit generates a signal to turn off the power tube and other devices; when the temperature returns to T L , the circuit generates a signal to turn on the power tube. The main technical indicators of the OTP circuit include: power supply voltage range, thermal oscillation, etc. [0003] figure 1 It is an existing OTP circuit structure. where M 1 -M 4 , Q 0 , Q 1 , and the resistor R 0 Constitute a proportional to absolute temperature (Proportional To Absolute Temperature, PTAT) current generation circuit. m 5 , R 1 and Q 3 Constitute the reference volta...

AI Technical Summary

Problems solved by technology

[0004] There are three disadvantages in this circuit structure: First, the circuit lacks a start-up circuit

If for some reason the gate voltage of M1 is high, the M 3 If the gate voltage is low, the whole circuit will not work normally

Second, the resulting PTAT current is not linear enough with temperature

[0006] It can be seen that their gate-source voltages are not equal, and they have the same gate voltage, so their source voltages are not equal, which will cause Q 0 and Q 1 , R 0 The resulting PTAT current is not linear enough with temperature

Third, M 2 and M 5 and M 2 and M 6 The resulting current mirror is not accurate

This will cause its jump temperature to be unstable under different supply voltages

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