Anti-radiation bipolar temperature monitoring circuit

Abstract

The invention provides an anti-radiation bipolar temperature monitoring circuit. The temperature monitoring circuit comprises a temperature sensor circuit, a positive feedback amplifying circuit and an amplifying output circuit; the temperature sensor circuit uses a NPN transistor to follow the reference voltage VREF of a bipolar voltage stabilizer, so that temperature sensing is achieved, and a signal is output to the positive feedback amplification circuit; the positive feedback amplification circuit amplifies the output signal of the temperature sensor circuit and outputs the amplified signal to the amplification output circuit; the amplification output circuit carries out sampling amplification on the output signal of the positive feedback amplifier and controls the output of a bipolarvoltage stabilizer output power transistor. When the junction temperature of a bipolar linear voltage stabilizer chip is higher than a safe working temperature, the bipolar voltage stabilizer outputpower transistor is turned off. The temperature monitoring circuit has the hysteresis characteristic, so that the linear voltage stabilizer is prevented from being frequently started at a temperatureclosing point; the function temperature of the chip cannot be sufficiently lowered.

Description

technical field [0001] The invention relates to the field of analog integrated circuits, in particular to an anti-radiation bipolar temperature monitoring circuit. Background technique [0002] Linear regulators are an important part of today's electronic systems, and are developing towards high power density, high conversion efficiency, high integration, low voltage output, and fast load transient response. The output adjustment tube of the bipolar linear regulator uses a PNP power transistor to achieve low dropout characteristics; it uses an NPN power transistor to achieve a faster load transient response, but its input and output pressure difference is large; its output current capability can be During the use of the circuit, if the heat sink is not used properly in the application of high current output or an abnormal overcurrent state occurs, the junction temperature of the linear regulator chip may be higher than the safe operating temperature, and the circuit will not...

AI Technical Summary

Problems solved by technology

The output adjustment tube of the bipolar linear regulator uses a PNP power transistor to achieve low dropout characteristics; it uses an NPN power transistor to achieve a faster load transient response, but its input and output pressure difference is large; its output current capability can be During the use of the circuit, if the heat sink is not used properly in the application of high current output or an abnormal overcurrent state occurs, the junction temperature of the linear regulator chip may be higher than the safe operating temperature, and the circuit will not work normally. It may even damage the chip and cause the circuit function to fail. Therefore, it is necessary to design a temperature monitoring circuit to detect the junction temperature of the chip and control the output of the linear regulator.

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