High-precision temperature detection circuit of battery management system

Abstract

A high-precision temperature detection circuit of a battery management system includes a control unit, a temperature detection unit, a voltage division switching unit, an analog-to-digital converter and a temperature sensor. The input end of the voltage division switching unit is connected with an external power supply, the output end is connected with the input end of the temperature detection unit, a first control input end is connected with a first control output end of the control unit, a second control input end is connected with a second control output end of the control unit, and a third control input end is connected with a third control output end of the control unit. Through the voltage division switching unit, in a temperature interval corresponding to the temperature sensor, the control unit outputs a signal to switch on a corresponding voltage division branch in order to realize segmented measurement of the circuit. It is ensured that the voltage input to the analog-to-digital converter is close to the optimal detection voltage point V0 of the analog-to-digital converter, and the measurement precision of the detection circuit is improved.

Description

technical field [0001] The invention relates to the field of temperature detection, in particular to a high-precision temperature detection circuit of a battery management system. Background technique [0002] like figure 1 Shown is the schematic diagram of the circuit principle of the temperature detection circuit in the prior art, including a thermistor, a temperature detection unit 10 and an analog-to-digital converter (not marked in the drawings), the input end of the temperature detection unit 10 is connected to an external power supply, and the temperature detection end (i.e. attached figure 1 The Rntc port in) is connected to the temperature signal output terminal of the thermistor, and the output terminal (that is, the attached figure 1 The Input_AD port in) is connected with the input end of the analog-to-digital converter. which detects the voltage V through the analog-to-digital converter AD =Vcc_NTC / (R 1 +R ntc )={[AD digital value] / 2 a}*V ref , where, Vc...

AI Technical Summary

Problems solved by technology

while in figure 1 In the temperature detection circuit, it is impossible to ensure that the voltage input to the analog-to-digital converter is stable in the voltage range [V1, V2], so the measurement accuracy of the analog-to-digital converter cannot be guaranteed to be optimal.

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