Circuit of high-accuracy pressure transmitter

Abstract

The invention belongs to a pressure sensing technique and relates to circuit design of a high-accuracy pressure transmitter. In combination with the transmission characteristics of a piezoresistive SOI (Silicon on Insulator) pressure-sensitive device and a differential amplification circuit at different temperature conditions, the compensation of the temperature error of the output signal of the pressure transmitter is realized through a precision resistor network. Commonly used temperature compensation devices such as thermistors and diodes are not needed to be used in the circuit of the high-accuracy pressure transmitter, the temperature compensation of the pressure transmitter is realized only through four groups of precision fixed resistors and the errors of the pressure transmitter are reduced; and the applicable temperature range of the pressure transmitter which is designed by using the circuit is negative 55 DEG C to 175 DEG C and the output errors within the full temperature range are smaller than plus or minus 0.5% FS. The high-accuracy pressure transmitter has the advantages of small size, light weight, strong interference-resistant capability, stable output and simple and convenient technological process, and is suitable for large-scale production.

Description

technical field [0001] The invention belongs to the circuit design technology of an aviation pressure transmitter, and relates to a circuit of a pressure transmitter. Background technique [0002] A pressure transmitter is a device that converts the pressure signal to be measured into a specified electrical signal, and transmits the electrical signal to an indicator or a computer. With the development of the aviation industry, pressure transmitters are required to have high precision, good stability, small size, and light weight; they can adapt to harsh working environments, such as the temperature range of the working environment is -55°C to 175°C, and Contains complex electromagnetic interference signals. The high-precision pressure transmitter was invented to meet the needs of the aviation industry for high-end pressure transmitters. The realization of a high-precision pressure transmitter depends critically on the circuit design and temperature compensation method. At...

AI Technical Summary

Problems solved by technology

At present, high-precision pressure transmitters are generally realized by digital compensation; and at present, the maximum operating temperature of domestic and foreign military digital devices and special conditioning chips such as A / D conversion, microprocessor, D / A converter, etc. 125°C, unable to meet the use requirements under higher temperature conditions

The analog temperature compensation is usually implemented by thermistors, diodes and other devices. The temperature compensation accuracy of thermistors is not high, and the temperature compensation circuit of diodes is more complicated; Poor, it is difficult to meet the requirements of the aviation industry for pressure transmitters

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