SPRUJC0 April 2024
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 verifies 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.
Three PGA signals are available at the device pins: PGA_INP (positive input), PGA_INM (negative input), and PGA_OUT (output). PGA_OUT supports op-amp output filtering with RC components. The filtered signal is available for sampling and monitoring by on-chip ADC and CMPSS modules. The F28P55x LaunchPad includes 3x3 PGA header, J10. PGA signals are connected to the PGA modules on the device when switch S6 is set appropriately, see Table 3-6. J10 header has the PGA_INP, PGA_INM, and GND signals available for each of three PGA modules.