On the frequency limitations of SC filters

Representative closed-form expressions are derived for a stray-insensitive integrator which describe the combined influence of the amplifier finite gain and finite bandwidth and of the nonzero on-resistance of the switches. In this way, a technology-dependent upper frequency limit is obtained for the application of typical stray-insensitive switched-capacitor circuits. The deteriorating effect of switch-on resistance and stray capacitance is also derived for integrator circuits comprising unity-gain amplifiers. However, the results obtained shown that they are too much affected by the parasitic capacitances to be a serious alternative for monolithic high precision filters.