Voltage Divider
Last modified by Microchip on 2023/11/09 09:03
The following image of the circuit 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).
Advantages:
- Simplicity
- Ratiometric output (with Analog-to-Digital Converter (ADC) using VDD as its reference voltage)
- Detection of open sensor due to failure
Disadvantages:
- Poor common mode noise rejection
- Voltage is non-linear with resistance
Sensor Examples:
- Thermistor
- Resistive Temperature Detector (RTD)
- Magneto-resistive compass