Figure 1-1 shows the block diagram of the PGA module. The active component in the PGA is an embedded op-amp that can be configured as a non-inverting or inverting amplifier with internal feedback resistors. These internal feedback resistor values are paired to produce software-selectable voltage gains. Bringing these gain resistors internal to the device increases matching and temperature drift stability compared to the typical external gain-setting resistors.

Three PGA signals are available at the device pins:

• PGA_INP is the positive input to the PGA op-amp.
• PGA_INM is the negative input to the PGA op-amp.
• PGA_OUT supports op-amp output filtering with RC components. The filtered signal is available for sampling and monitoring by the on-chip ADC and CMPSS modules. For more information, see the device data manual.

Please note that PGA_OUT_INT is an internal signal at the op-amp output, which is available for sampling and monitoring by the internal ADC and CMPSS modules.

Analog pins and internal connection for the device are given in the Analog Subsystem chapter of the Technical Reference Manual.