Comparison of Noise Performance of FET Transimpedence Amp/Switched Integrator

Low-input current FET operational amplifiers are universlly used to monitor photodetector, or more commonly photodiode currents. These photodetectors bridge the gap between a physical event, light, and electronics. There are a variey of amplifier configurations to select from and the choice is based on noise, bandwidth, offset, and linearity. A considerable amount has been written on the performance of this traditional transimpedance amplifier. This topology has dominated applications such as CT scanners, star-tracking instruments, electron microscopes, etc., where a light-to-voltage conversion is required.