INA114RTD precision temperature measurement circuit

INA114 has high sensitivity, high input impedance (10lOn), high common mode rejection ratio (not less than 115 dB), low drift
(maximum voltage drift 50Lr,V, maximum temperature drift 0.25 VV/aC), adjustable gain (L— 10000) instrument amplifier. The working
power supply range is ±2.25~±18V, and the input can withstand ±40V overvoltage. INA114 is very suitable for sensor circuits. The precision temperature measurement circuit
    formed by it and the thermal resistor RTD is shown in Figure 1-10. REF200 is a dual lOO pL.A precision current source. The value of Rs should be equal to the resistance value     of the thermal resistor RTD at ooc . In this way , at ooc, the (+) and (1) inputs of INA 114 are at the same potential at oac. The output is 0. In the temperature measurement state, as the temperature changes, the resistance of the RTD changes accordingly, and the potential of the IIVA114(+) terminal also changes, and after amplification, a signal voltage of a certain amplitude is output. Rc is the gain adjustable resistor, the gain G=1 +50kfl/Rc, and the adjustment range is 1-10000. The output voltage is vo=C (v+.-v-).