5.1 Inverting Amplifier

The inverting amplifier configuration requires a biasing source (Vbias) that comes from an internal analog signal or from an external reference. Vbias level shifts the output of the OPA module and subtracts the scaled signal from the level-shift. Inverting amplifiers are commonly used to invert signals or for signals that need to be scaled up or down. The internal resistor ladder of the OPA module can be used to implement the OPA module (see Figure 5-1). The code snippet in 5.1.1 utilizes the internal resistor ladder and the Vdd/2 internal signal for a gain of -3 after shifting.