CIRCUIT060097

Some MSP430™ microcontrollers (MCUs) contain configurable integrated signal chain elements such as op-amps, DACs and programmable gain stages. These elements make up a peripheral called the smart analog combo (SAC). For information on the different types of SACs and how to leverage their configurable analog signal chain capabilities, visit MSP430 MCUs smart analog combo training. To get started with your design, download the MSP430 transimpedance amplifier circuit design files. The transimpedance op amp circuit configuration converts an input current source into an output voltage. The current to voltage gain is based on the feedback resistance. The circuit can maintain a constant voltage bias across the input source as the input current changes, which benefits many sensors. The characteristics of the Transimpedance Amplifier (TIA) module in MSP430FR2311 make it especially suited for this functionality; however, this circuit can also be implemented with the MSP430FR2311 SAC_L1, or with the MSP430FR2355 SAC_L3 with additional built-in DAC and PGA capabilities. The output of these integrated amplifiers can be sampled directly by the on-board ADC or monitored by the on board comparator for further processing inside the MCU.