Temperature sensing device and method proportional to absolute temperature (PTAT)

Abstract

The invention discloses temperature sensing device and method proportional to absolute temperature (PTAT), which can reduce the sensing error caused by mismatching of circuit components. The temperature sensing device proportional to absolute temperature (PTAT) comprises a control unit, a sensing unit and a computing unit, wherein the sensing unit comprises at least a pair of circuit components with matching relation, and the relation of connection of the pair of circuit components is exchanged to generate first connection configuration and second connection configuration; the sensing unit respectively senses an absolute temperature under the first connection configuration and the second connection configuration to generate a corresponding first voltage value and a corresponding second voltage value; the computing unit can generate a PTAT voltage value according to the first voltage value and the second voltage value; and the control unit can generate a control signal to the sensing unit to control the sensing unit to be switched between the first connection configuration and the second connection configuration.

Description

technical field [0001] The invention relates to a temperature sensing circuit, in particular to a proportional to absolute temperature (PTAT) sensing device and method. Background technique [0002] A proportional to absolute temperature (PTAT) sensing circuit is a commonly used temperature sensing circuit, which is suitable for situations where accurate temperature detection is required. For example, in a global satellite positioning (GPS) device, the oscillation frequency of the local oscillator (local oscillator) needs to be very accurate in order to maintain the accuracy of positioning, but the oscillation frequency will change with the temperature, so the GPS device needs to be able to accurately sense The temperature is measured to help the local oscillator generate an appropriate oscillation frequency. [0003] The conventional PTAT temperature sensing circuit uses a pair of bipolar junction transistors (BJT) for temperature sensing, such as figure 1 shown. exist ...

AI Technical Summary

Problems solved by technology

[0013] The aforementioned mismatching situation will lead to the V obtained in formula (2) PTAT Errors are generated, which affect the accuracy of the PTAT temperature sensing circuit 10, and further experiments can be found that the mismatch between the transistors Q4 and Q5 and between the two input terminals of the amplifier 11 is the most important factor for the sensing error of the PTAT temperature sensing circuit 10. main source

Images