The circuit below shows a voltage divider (RSEN and R3) that converts the sensor resistance to a voltage. The MCP6XXX op amp acts as a voltage follower (buffer). If the op amp and resistors are ideal then VOUT = (VDD) R3/(RSEN + R3).
- Ratiometric output (with Analog-to-Digital Converter using VDD as its reference voltage)
- Detection of open sensor due to failure
- Poor common mode noise rejection
- Voltage is non-linear with resistance