HART协议通用压力变送器的设计

Design of General HART Protocol Pressure Transmitter

本文阐述了目前压力变送器采用的传感器种类,并说明采用传统的信号处理电路需要不同的电路与之配合使用,造成产品种类多,不宜量产。因此本文详细介绍了一种崭新的设计思想,采用这种电路能支持现有的各种压力传感器。新电路可以提供软件可控的恒压、恒流输出给传感器,并可以采集两路差分或4路单端输入信号。其后介绍电路采用的4级抗干扰保护措施以及树脂密封主电路和6面电磁屏蔽的可靠性和抗干扰设计方法及其在HART数据通信方面的突出优势。

This paper firstly illustrates the different sensor types that present pressure transmitters usually applied. For traditional transmitter, it requires different signal conditioning circuits for different sensors, which finally leads to the great variety of products,thus quantity production not available.This paper introduces a brand new design concept, which could be applied to all present pressure sensors.The new circuit could provide software-configurable constant voltage or constant current output to the sensor, meantime gather the 2-channel differential or 4-channel single-end ADC input signal. In the latter part of the paper, it mainly focuses on the 4-level anti-jamming protection measures, as well as the reliability of resin seal main circuit and 6-side electromagnetic shield. Also it has explained the antijamming design method as well as its outstanding advantage on HART data communication.