M. Arivalagan, K. R. Aravind Britto and R. Vimala
Transimpedance Amplifier Design for Millisecond Current Pulses
Dynamic Systems and Applications 30 (2021) No. 10, 1608 – 1621
https://doi.org/10.46719/dsa202130.10.05
ABSTRACT.
A 109 V/A gain, 5 kHz bandwidth transimpedance amplifier is designed and tested for noise limits close to the theoretical prediction. The amplifier is tested to amplify tiny current pulses coming out of Faraday cup detectors. Noise voltage referred to output (RTO) is measured and the input-referred current noise (RTI) is calculated and found to be 270 µVRMS and 12.4 fA close to the theoretical limit of 246 µVRMS and 10 fA . We have concentrated on the amplifier topology, choice of op-amp, the feedback resistor and other components to optimize noise. Special attention has been given to the reduce the parasitic capacitance of the printed circuit board (PCB) and feedback resistor RF package to further reduce and optimize the noise.
Keywords: Ion Mobility Spectrometer, Transimpedance amplifier, analytical instruments, amplifier noise, bandwidth.