The Programmable Gain Amplifier (PGA) is used to amplify an input voltage for the purpose of increasing the effective resolution of the downstream ADC and CMPSS modules.
The integrated PGA helps to reduce cost and design effort for many control applications that traditionally require external, stand-alone amplifiers. On-chip integration ensures that the PGA is compatible with the downstream ADC and CMPSS modules. Software-selectable gain and filter settings make the PGA adaptable to various performance needs.
The PGA has the following features:
The active component in the PGA is an embedded operational amplifier (op amp) that is configured as a noninverting amplifier with internal feedback resistors. These internal feedback resistor values are paired to produce software selectable voltage gains.
Three PGA signals are available at the device pins:
PGA_OUT is an internal signal at the op amp output. It is available for sampling and monitoring by the internal ADC and CMPSS modules. Figure 5-36 shows the PGA block diagram.