A dc-dc converter circuit based on over-temperature protection threshold trimming

Abstract

The application discloses a DC-DC converter circuit based on over-temperature protection threshold adjustment, and an over-temperature detection module comprises: a first transistor circuit, the base of the transistor is connected with the reference voltage VBG output end of a band gap reference module, a positive temperature coefficient voltage proportional to absolute temperature is generated; a voltage dividing circuit input end is connected with the positive temperature coefficient voltage output end, the positive temperature coefficient voltage is divided to generate a detection voltage; a second transistor circuit, the base of the transistor is connected with the detection voltage output end, an over-temperature protection signal OTP is output to shut down the main circuit of the converter; an adjustment resistance circuit receives a digital adjustment signal; the digital adjustment signal changes the voltage dividing ratio of the positive temperature coefficient voltage divided to the detection voltage by controlling the equivalent resistance value of the adjustment resistance circuit; the change direction of the voltage dividing ratio is opposite to the change direction of the reference voltage VBG caused by adjustment. The application significantly improves the accuracy, consistency and overall reliability of the over-temperature protection threshold.

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