SBOA521 June 2021 OPA3S328
The programmable gain TIA provides flexibility to measure a wide range of photodiode current while ensuring the amplifier remains inside its linear range. The OPA3S328 dual op-amp offers low input bias current, high DC precision performance, low noise, and high bandwidth, providing an optimal choice for transimpedance amplifier applications. The device incorporates two sets of low leakage, low capacitance, analog switches useful for the configuration of programmable gain amplifiers in a single device integrated solution.
The preceding discussion shows some of the design trade-offs when implementing programmable transimpedance amplifiers using analog switches, and a Kelvin-sense circuit topology to eliminate TIA gain error, gain error drift, and non-linearity due to the switch on-resistance. This document provides the information to assist the design engineer in implementing the programmable TIA design according to the specific application needs.