Programmable Gain Amplifier (PGA)

Overview

General Description

Symbol Diagram

The PGA implements an opamp-based, non-inverting amplifier with user-programmable gain. This amplifier has high input impedance, wide bandwidth and selectable input voltage reference. It is derived from the switched capacitor/continuous time (SC/CT) block.

The gain can be between 1 (0 dB) and 50 (+34 dB). The gain can be selected using the configuration window or changed at run time using the provided API. The maximum bandwidth is limited by the gain-bandwidth product of the opamp and is reduced as the gain is increased. The input of the PGA operates from rail to rail, but the maximum input swing (difference between Vin and Vref) is limited to VDDA/Gain. The output of the PGA is class A, and is rail to rail for sufficiently high load resistance.

Features
  • Gain steps from 1 to 50
  • High input impedance
  • Selectable input reference
  • Adjustable power settings
Support