Gated Baseline Restorer with Adjustable Asymmetry

Abstract

A baseline restorer (BLR) for pulse amplifiers is described in which current to the memory capacitor can be gated off during a pulse. This technique reduces the BLR recovery time without introducing artifacts when a short-period undershoot accompanies the input signal. The gating and reset thresholds are adjustable, as is the BLR symmetry. Tests with a pulse generator show that the baseline shift with 5V pulses at duty factors up to 75% is less than 1mV. When the signal source is a radiation detector, the gated BLR is usable at duty factors up to 90%.