Reduction the effects of opamp finite gain and offset voltage in LDI termination with a minus one half delay of SC ladder filters

Abstract

In this paper a combined approach for reducing the effects of op amp imperfections (finite gain A and offset voltage V_OS) in first-order SC cell, realizing LDI (lossless discrete integrator) termination with a minus one half delay is presented. First, the conventional integrator is replaced with gain- and offset-compensated (GOC) integrator. Next, the gain errors m(ω) and the phase errors θ(ω) are further reduced by using the precise op amp gain approach in the GOC structure. The variation of the dc gain A from its nominal value A₀ is taken into account.