基于ADuC847的温度校准仪的设计

The design of a temperature calibrator based on ADuC847

ADuC847是ADI公司推出的微转换芯片,利用其片内集成的24位∑-△模数转换器把模拟电压信号转换为数字信号。电压信号的产生是采用三端稳压集成电路LM317与LM337产生恒定的10mA电流源,流过随温度变化的Pt100热电阻转化而来。为了减少热电阻引线误差,该设计使用了四线制法测量电阻两端的电压,提高了温度信号的采集精度。

vert into digital ADuC847 is a MicroConverter of Analog Device INC. The signals of analog voltage consingal through the AD of 24 bits ∑-△,which is internal IC of the ADuC847. The constant 10 mA current supplied by the LM317 and the LM337 that are based on three ends constant voltages integrated circuit. The current streams into the changing resistance of Pt100 with varente temperature, then the signals of voltage are acquiered. The design applies the four wire temperature measuring the voltage of resistance for eliminating lead wire resistance, so the precise of acquiring the singals of temperature is promoted.