High-precision temperature monitoring circuit

Abstract

The invention discloses a high-precision temperature monitoring circuit which comprises a temperature sensor, a resistor R1, a resistor R2, a triode, a resistor R3 and an optical coupler U, wherein after the resistor R1 and the resistor R2 are connected in series, a non-public end of the resistor R2 is connected onto the temperature sensor; a non-public end of the resistor R1 is connected onto a power supply; public ends of the resistor R1 and the resistor R2 are connected with a base electrode of the triode; an emitting electrode of the resistor R1 is connected onto the power supply; a collector electrode is connected onto the resistor R3, and the other end of the resistor R3 is connected onto an input end of the optical coupler U; a pull-up resistor R4 is connected onto the output end of the optical coupler U; and the temperature sensor is connected with the power supply at the same time. The high-precision temperature monitoring circuit has the advantages as follows: the output of the optical coupler is isolated, common-mode voltage on a line is restrained, and the monitoring precision is improved.

Description

technical field [0001] The invention relates to the field of integrated circuits, in particular to a high-precision temperature monitoring circuit. Background technique [0002] In many occasions, the control of temperature is very important. Such as warehouses, basements, greenhouses or large shopping malls. Such as figure 2 Shown is the existing high-precision temperature monitoring circuit, which uses amplifiers and logic circuits to monitor the temperature. When the temperature is remotely monitored, although it can well suppress the rise of the minimum operating voltage, there is a common-mode voltage on the line, which will affect the input signal and make the monitoring accuracy not high. Contents of the invention [0003] The invention provides a high-precision temperature monitoring circuit, which uses an optical coupler to isolate the output, suppresses the common-mode voltage on the line, and improves the monitoring accuracy. [0004] In order to solve the a...

AI Technical Summary

Problems solved by technology

When monitoring the temperature remotely, although it can well suppress the increase of the minimum working voltage, there is a common-mode voltage on the line, which will affect the input signal and make the monitoring accuracy not high.

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