Reduction of operational amplifiers finite gain effects in switched-capacitor biquads

A combined approach for reducing the errors in the pole frequency f p, the pole Q - factor Qp and the magnitude at the pole frequency Hp, 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 ƒp / ƒp, Δ Qp / Qp and Δ Hp / Hp are minimized by modifying three capacitances: two feedback capacitances and feed forward capacitance. The effectiveness of this approach is demonstrated by designing a band pass biquad

Comparative Analysis of Two Gain-and Offset- Compensated Four-Phase Switched-Capacitor Integrators Based on The Second-Order Adams-Bashworth's Integration Method

Abstract: Gain-and offset-compensated (GOC) modifications of four-phase inverting and noninverting switched-capacitor integrators based on the second-order Adams-Bashworth's integration method are presented. Analytical expressions for the gain, phase and offset voltage errors are derived and compared with the corresponding errors of the earlier ones compensated integrators. The two pairs of GOC integrators are used as building blocks of a bandpass biquad. The performances of the resulting filters are also compared

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

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