Programmable Gain Amplifier

Last modified by Microchip on 2023/11/09 09:03

The circuit below shows an MCP6SX2 Programmable Gain Amplifier (PGA) used to condition multiple sensors. The PGA allows the user to select an input sensor and gain with the Serial Peripheral Interface (SPI) bus. It can also help linearize non-linear sensors, e.g. thermistors.

Programmable gain amplifier circuit

Advantages

  • Multiple sensors
  • Complementary Metal Oxide Semiconductor (CMOS) input (high impedance and low bias current)
  • Digital control (SPI) of input and gain
  • Linearization of non-linear sources

Disadvantages

  • Input stage distortion
  • Amplifies common mode noise
  • Needs Microcontroller Unit (MCU) and firmware

Sensor Examples

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