On the noise performance of a novel delay-switched gated integrator

Abstract

For trapezoidal filtering, widely used for diminishing the harmful effect of the ballistic deficit, a modified version of the gated integrator is suggested. In this delay-switched gated integrator the true integration is delayed with respect to the beginning of the pulse, and for the delay period the true integration process is approximated with a low-pass filter. The paper theoretically compares the noise behavior of the delay-switched gated integrator and that of the gated integrator. The noise calculations are based on the concept of the step- and delta-noise residual functions and they are performed in three cases. In the first case the standalone shaping circuits are analyzed, in the second case they are preceded by a fast baseline restorer and in the third case they are preceded by a baseline restorer of finite time constant. It is shown that the novel delay-switched gated integrator preceded by a baseline restorer can be a good alternative to gated integrators.