Temperature transmitter hardware framework and schematic diagram

蓝色天使

Temperature transmitter hardware framework and schematic diagram [Copy link]

 

The overall hardware framework structure is shown in the figure (attachment):

1. The constant current source and op amp design of the acquisition part are the key to the design. The 2.5V voltage reference accuracy and temperature drift of the constant current source front end determine the current source accuracy. To ensure a smaller offset voltage and higher current accuracy, the op amp uses a dual power supply. After the thermal resistor is output by the constant current source, the voltage is differentially amplified by the op amp to the 24ADC LTC2400. The mainboard reads the data of the LTC2400 through the host SPI interface.

2. Purchase GP8212 conversion IC at the output end, and output the collected thermal resistance signal through 15-bit DA. In order to ensure the output accuracy, the output current is differentially sampled and amplified to the 8212 feedback end. The output current I=(2.5*(DATA/0X7FFF))/R17.

peiqiu

Low power single chip two-wire intelligent transmitter Introduction Two-wire thermal resistance temperature transmitter is to convert the temperature signal linearly into 4~20mA DC standard output signal. Since most of the analog two-wire temperature transmitters are composed of discrete components, the temperature drift is relatively large.

Jacktang

Thank you for sharing the overall hardware framework structure diagram