ADT70 platinum thermal resistance temperature measurement circuit

The basic electrical parameters of AD170 are as follows: temperature coefficient 25ppm/"C, temperature measurement accuracy ±1℃, maximum temperature measurement range is -200
~+1000qC, working power supply +5v or t5v, working temperature range is -40-+125℃.
    ( 1) PRTD platinum thermal resistance temperature measurement circuit. Since ADT70 integrates voltage source, current source and amplifier circuit,
the peripheral circuit is very simple when using it for temperature measurement. As shown in Figure 1-47, ADT 70 platinum thermal resistance Resistance temperature measurement circuit .
  PRTD is a 4-wire (one end of the 2 wires is connected to +INIA, /OUTB, and the other end of the 2 wires are connected to ground and the ⑩ pin of the operational
amplifier ) ​​temperature measurement platinum resistor, the ruler is the reference resistor, and the matching current Source output current, OUTA and /OUTB are added to the reference
resistor, instrument amplifier - UNIA and platinum resistor, instrument amplifier + INIA respectively. The temperature measurement signal output by the platinum resistor
is amplified by the operational amplifier and instrument amplifier at the same time and then output from pin ⑩. The gain of the instrument amplifier
is determined by the adjustable external resistor Rc
    G =49. 9kfl/Rc