The design of a fast preamplifier

A new fast preamplifier circuit designed by us is introduced brieflyinthis paper.It is suitable for use with some fast detectors,to amplify small and fast signals from the fast detectors.This circuit is a pure direct-coupled amplifier with high voltage gains(A_v900),fast rise time(t_r4ns),and low noise(V_N14nV)referred to the input).In order to restrain the dc drift a Bessel filter and an inverting adding circuit were used in our design.This circuit has a good gain stability.This fast preamplifer has been used in our experiment to amplify signals from Si avalanche photodiode detector,also,been used in beam diagnosis system of HIRFL-CSR to amplify the small signals from the beam position probe or signals from beam phase monitor.