On-chip digital temperature sensor with optimized linearity

Abstract

The invention discloses an on-chip digital temperature sensor with optimized linearity, which includes a ring oscillator for outputting a ring oscillator clock signal whose cycle varies with temperature; and also includes a time amplifier whose input is the ring oscillator clock signal , so as to obtain a pulse signal with several cycle lengths of the ring oscillator clock signal; the digital temperature sensor also includes a counter whose input is the above pulse signal and a reference clock signal. When the pulse signal arrives, the reference clock is used to count , until the end of the pulse signal, so a count value with the reference clock period as the unit pulse signal length is obtained; the digital temperature sensor of the present invention has good linearity while retaining the advantages of simple structure, small area and low power consumption. With the advantages of wide measurement temperature range and high precision, the external crystal oscillator can be omitted, which saves the cost.

Description

technical field [0001] The invention relates to integrated circuits, in particular to a digital temperature sensor. Background technique [0002] On-chip temperature sensors generally have two architectures. One is to use an analog-to-digital converter (ADC) in the voltage domain to detect a bandgap voltage proportional to absolute temperature to detect temperature; this bandgap voltage is usually the VBE of two triodes (The difference between the emitter and base voltages of the transistor BJT) is the difference ΔVBE. This kind of temperature sensor has the advantages of high precision, good linearity, wide measurement temperature range and low voltage sensitivity. However, due to the use of ADC for detection, its disadvantages are large area and large power consumption; the second is in the time domain , to detect temperature by detecting the on-chip clock whose clock period varies with temperature. Since no ADC is required, this temperature sensor has the advantages of ...

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Problems solved by technology

[0010] α is approximately equal to 0.7, so the linearity of the temperature sensor with this structure is not good enough, which limits the temperature range it can measure and reduces the accuracy

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