Reduction of Operational Amplifiers Finite Gain Effects in Switched-Capacitor Biquads

Abstract

Abstract: A combined approach for reducing the errors in the pole frequency f p, the pole Q- factor Q p and the magnitude at the pole frequency H p, of switched capacitor biquads is presented. First, the conventional integrators in the biquads are replaced with gain-and offset-compensated integrators. Next, the errors Δ f p / f p, Δ Qp / Qp and Δ H p / H p are minimized by modifying three capacitances: two feedback capacitances and feed forward capacitance. The effectiveness of this approach is demonstrated by designing a bandpass biquad