1.3.1 Scaling with an Operational Amplifier Peripheral

One way to scale a signal dynamically is to use the operational amplifier peripheral. In the circuit shown in Figure 1-5, resistors R1 and R2 provide negative feedback that sets the gain of the op amp.

Figure 1-5. Schematic of a Noninverting Amplifier

Generally, resistors R1 and R2 are external components. But on some op amp peripherals, R1 and R2 are available from the internal resistor ladder, which removes these parts from the Bill of Materials (BOM).

Other op amp configurations are also possible, depending on the number of op amps on the device. A few of the possibilities are listed below:

Inverting Amplifier (1 op amp)
Differential Amplifier (2 op amps)
Cascaded Amplifier (2+ op amps)
Instrumentation Amplifier (3 op amps)

Find more information about these configurations in the device data sheet or related technical documentation.