Temperature sensor

Abstract

The invention provides a temperature sensor comprising the following: a first temperature sensing circuit configured to generate a sensing current associated with temperature; a second temperature sensing circuit reference circuit configured to generate a reference current independent of temperature; a first current controlled oscillator configured to convert the sensing current to sensing frequency; a second current controlled oscillator configured to convert the reference current to reference frequency; and a processor configured to normalize the sensing frequency by using the reference frequency so as to generate normalized sensing frequency. Under a same process corner, the sensing frequency and reference frequency are affected by the process to the same extent. By using the referencefrequency to normalize the sensing frequency, the influence of a process deviation on an output can be greatly reduced. Therefore, the process deviation is diminished.

Description

technical field [0001] The invention relates to a temperature sensor, in particular to a temperature sensor that can be integrated on a chip. Background technique [0002] The CMOS temperature sensor is a sensor that can be integrated inside the chip. It is an indispensable analog circuit module inside the chip. It plays a very important role in the dynamic management of temperature in the chip and real-time monitoring of temperature. [0003] Current on-chip temperature sensors mainly include voltage temperature sensors, delay line temperature sensors and frequency temperature sensors. [0004] The voltage temperature sensor uses the voltage proportional to the temperature as the monitored physical quantity to obtain the corresponding relationship with the temperature. The voltage temperature sensor also needs to use an analog-to-digital converter (ADC). Although the accuracy is high, the circuit is complex and the power consumption is large. The delay line temperature sen...

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Problems solved by technology

[0004] The voltage temperature sensor uses the voltage proportional to the temperature as the monitoring physical quantity to obtain the corresponding relationship with the temperature. The voltage temperature sensor also needs to use an analog-to-digital converter (ADC). Although the accuracy is high, the circuit is complicated and the power consumption is large.

The delay line temperature sensor uses the characteristic that the delay of the inverter changes with the temperature, and uses the delay as a physical quantity to monitor the temperature. The circuit of the delay line temperature sensor is simple and can be realized by an all-digital circuit. The disadvantage is that it needs to obtain a higher delay. The linearity between time and temperature requires a lot of delay units in series, usually up to hundreds of inverters, which will seriously increase the chip area

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