Temperature sensor

Abstract

The invention relates to a temperature sensor, which comprises a reference generation circuit, a signal amplification circuit and an analog-to-digital conversion circuit, wherein the reference generation circuit is used for generating BE node temperature sensing voltage for sensing temperature and reference voltage; the signal amplification circuit comprises a first amplifier, a second amplifier,a third amplifier and a first summator which are used for amplifying and adding the BE node temperature sensing voltage and the reference voltage and outputting a sum signal containing the BE node temperature sensing voltage and the reference voltage and an amplification signal of the reference voltage; and the analog-to-digital conversion circuit is used for performing analog-to-digital conversion and generating a digital signal representing the ratio of the two signals. Compared with the prior art, the temperature sensor detects the temperature by sharing the reference voltage generated by the reference generation circuit and the BE node voltage of a bipolar transistor so as to eliminate the influence of mismatch of the redundant current mirrors on the BE node voltage, improve the precision of the temperature sensor, save power consumption and area and reduce the influence of the process tolerance of the bipolar transistor on the precision of the sensor.

Description

technical field [0001] The present invention relates to the field of sensors, in particular, to a temperature sensor based on CMOS. Background technique [0002] In many fields such as industrial and agricultural production monitoring, environmental control and scientific research, temperature is an important parameter that needs to be measured and controlled. Therefore, among various sensors, the temperature sensor is the most widely used one, and the integrated temperature sensor is mainly composed of temperature sensing, reference circuit, AD converter, control circuit, etc. Compared with the traditional temperature sensor, it has It has the advantages of high sensitivity, small size, low power consumption, good output characteristics, and can be directly connected with digital systems. [0003] At present, there are mainly two ways to realize the temperature detection of the integrated temperature sensor. [0004] figure 1 A temperature sensor commonly used today is s...

AI Technical Summary

Problems solved by technology

But its disadvantages are: it is necessary to test the error curve of the temperature, and it is necessary to use a single-chip microcomputer or an additional digital circuit to realize the compensation algorithm, and it is impossible to eliminate or reduce the influence of the bipolar transistor process tolerance on the temperature accuracy

The disadvantage is that the patent is only applicable to the second temperature detection method, and the detection temperature voltage generated by this method is linearly related to the temperature, and it is necessary to adopt technologies such as dynamic matching and chopping to return to zero to eliminate or weaken the bipolar transistor. The mismatch of the current mirror and the input offset voltage of the operational amplifier are affected by these non-ideal factors, and the circuit structure is complex

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