Totally integrated digital temperature sensor

Abstract

The invention discloses a totally integrated digital temperature sensor comprising a time offset rectification circuit and a time comparator, wherein the output end of the time offset rectification circuit is respectively connected with a temperature lagging strand and an adjustable reference lagging strand; the output end of the temperature lagging strand and the output end of the adjustable reference lagging strand are respectively connected with the input end of the time comparator, and the other input end of the adjustable reference lagging strand is connected with a current reference circuit; the output end of the time comparator is connected with an SAR control logic of which one output end is connected with the input end of the adjustable reference lagging strand; the other output end of the SAR control logic is connected with the input end of the time offset rectification circuit, and the other input end thereof is connected with a clock CK signal. The invention is compatible with the standard CMOS technology, can be totally integrated, lowers chip cost and is reliable and simple to realize. As the totally integrated digital temperature sensor, the invention can be widely applied in measuring temperature.

Description

technical field [0001] The invention relates to a temperature measurement technology, in particular to a temperature detection circuit of a temperature compensation crystal. Background technique [0002] Digitization, intelligence, integration and standardization have become the mainstream of today's temperature sensor technology development. The traditional system composed of signal unit, signal conditioning circuit, microprocessor and bus combination made by non-integrated technology is the fastest solution to realize smart sensors. However, it is obvious that this solution brings high cost and is not suitable for today's extremely competitive In wireless communication applications, the use of high-integration, low-cost standard CMOS technology is the inevitable direction of its development, and more and more temperature sensors use digital output as the input of the temperature display interface or the signal of other functional modules Input, not only realizes the digit...

AI Technical Summary

Problems solved by technology

This reference voltage requires process compensation and temperature compensation to achieve high precision, such as using chopping technology (CHOP) to reduce the offset of the op amp in the voltage reference circuit, adding a second-order or higher-order temperature compensation circuit, and using trimming technology to obtain accurate The voltage, etc., obviously this increases the difficulty of the design

In addition, to improve the accuracy of the temperature sensor, the number of output bits of the A / D conversion circuit needs to be increased, resulting in the need to use more analog voltage comparators, which greatly increases the chip area and increases the system cost.

Since the temperature sensing signal is a low-frequency signal, using ΣΔ-ADC can improve the accuracy of the temperature sensor, but this greatly increases the design complexity and power consumption

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