Digital piezoresistive pressure sensor circuit and digital piezoresistive pressure sensor

Abstract

The invention belongs to the field of pressure detection, and discloses a digital piezoresistive pressure sensor circuit and a digital piezoresistive pressure sensor, and the digital piezoresistive pressure sensor circuit comprises a piezoresistive pressure sensor chip, a variable gain amplifier, an A / D converter, a digital temperature sensor, an MCU and an interface unit. The piezoresistive pressure sensor chip is used for detecting external pressure to obtain a pressure voltage signal and sending the pressure voltage signal; the variable gain amplifier is used for receiving the pressure voltage signal and amplifying the pressure voltage signal to obtain an amplified pressure voltage signal; the A / D converter is used for receiving the amplified pressure voltage signal and performing A / D conversion to obtain an initial digital voltage signal; the digital temperature sensor is used for detecting the current environment temperature to obtain a temperature signal; and the MCU is used for receiving the initial digital voltage signal and the temperature signal, compensating the initial digital voltage signal according to the temperature signal, obtaining a digital voltage signal and outputting the digital voltage signal through the interface unit. The precision of the digital piezoresistive pressure sensor circuit is greatly improved, and the working temperature range is widened.

Description

technical field [0001] The invention belongs to the field of pressure detection, and relates to a digital piezoresistive pressure sensor circuit and a digital piezoresistive pressure sensor. Background technique [0002] At present, as a pressure detection device, analog pressure sensors are widely used in military and civilian fields such as aviation hydraulic detection systems, navigation systems, vehicle-mounted environmental monitoring systems, individual combat systems, oil exploration, oxygen production systems, and atomizers. . [0003] However, due to the following disadvantages of the analog pressure sensor: 1. The output of the analog pressure sensor is an analog voltage signal, and the subsequent system needs to perform A / D conversion before processing, which has low precision and increases system cost and complexity. , is not conducive to system matching and integration. 2. Poor anti-interference ability. The output of the analog pressure sensor is an analog v...

AI Technical Summary

Problems solved by technology

[0003] However, due to the following disadvantages of the analog pressure sensor: 1. The output of the analog pressure sensor is an analog voltage signal, and the subsequent system needs to perform A / D conversion before processing, which has low precision and increases system cost and complexity. , which is not conducive to system matching and integration

2. Poor anti-interference ability

The output of the analog pressure sensor is an analog voltage signal, and the analog signal is easily disturbed during the transmission process, which affects the stability of the subsequent system

3. Poor temperature characteristics

The temperature coefficient of the analog pressure sensor is relatively large. In the case of a large range of ambient temperature changes, the subsequent system needs to be equipped with a temperature compensation unit, which increases the volume and cost of the system.

4. Large non-linearity error

[0004] However, the current digital piezoresistive pressure sensor generally has a relatively complex structure, resulting in high cost. Although the detection accuracy has been improved compared with the analog pressure sensor, it still cannot meet the requirements of the high detection accuracy field.

Images