A temperature conversion method and low-power high-precision integrated temperature sensor

Abstract

The invention relates to a temperature conversion method and a low-power high-precision integrated temperature sensor. The low-power high-precision integrated temperature sensor is composed of a band gap reference circuit with a sensing core, a positive and negative synchronous switch capacitor integral circuit, a current source and a sampling capacitor dynamic element matching module, a clock generating circuit, a divider and buffer circuit and a fully differential analog-to-digital converter. The sensing core circuit in the traditional technology and the band gap reference circuit are combined and integrated, so that the circuit structure is simplified; the current source dynamic element matching module is arranged and thus a base-emitter junction voltage difference in proportion to the absolute temperature is generated, wherein the polarity of the voltage difference changes alternately; with the novel positive and negative synchronous switch capacitor integral circuit, the improved temperature conversion function is completed and the dynamic range utilization rate of the analog-to-digital converter is improved; dynamic element matching is carried out on the sampling capacitor, thereby improving the integral accuracy; and the analog-to-digital converter is used for carrying out quantization processing on an effective temperature signal to provide a digital output. Therefore, the temperature error and circuit power consumption of the sensor can be effectively reduced; and the method and the sensor are suitable for the low-power high-precision temperature sensing application.

Description

technical field [0001] The invention relates to the field of sensors, in particular to a temperature conversion method and a low-power-consumption high-precision integrated temperature sensor. Background technique [0002] The basic implementation method of the current CMOS semiconductor temperature integrated sensor based on the principle of ratio measurement is: the base-emitter junction voltage difference ΔV of the parasitic substrate PNP transistor in the standard CMOS integrated circuit process under different current densities BE It is a highly linear voltage proportional to the absolute temperature, and it is linearly amplified to a suitable amplitude (called V PTAT ) to a temperature-independent reference voltage V REF By comparison, a voltage proportional function (temperature conversion function) proportional to temperature can be obtained. This proportional function can be quantized and output by an analog-to-digital converter (such as a successive approximation ...

AI Technical Summary

Problems solved by technology

Due to the limitation of the temperature conversion function, the temperature sensor based on the proportional measurement principle in the prior art has a low utilization rate of the dynamic range of the analog-to-digital converter, which does not exceed 60%, resulting in a waste of the resolution of the analog-to-digital converter

In the prior art, the bandgap reference circuit and the sensor core circuit of the temperature sensor are independent of each other, which increases the error source of the temperature sensor to a certain extent, increases the complexity and power consumption of the circuit

In addition, the low-power temperature sensor solution in the existing technology, in order to pursue low power consumption, seldom uses the necessary precise circuit technology, resulting in a large temperature error of more than ±1°C, and the actual use value is not high.

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