Figure 8. This circuit uses a voltage excitation configuration for ratiometric measurement. The general ADC conversion formula is: where V IN is the ADC input voltage, V REF is the reference voltage ...

Thus, the circuit provides stable and identical voltages at the bottom of the platinum RTD and R REF . The circuit also buffers this voltage using the internal amplifier of IC 1 . A 1-kW resistor in ...

This circuit applies heating power for about 90% of the time and measures the RTD thermoelectric potential during the approximately 10% of off-time (Fig. 1). Two switches are required.