Switched-capacitor biquad building block with offset-insensitive time-continuous feedback integrators

A fully-differential switched-capacitor biquad building block is presented which provides total insensitivity to the operational amplifier (op amp) offset voltage, reduces the 1/f noise, and ensures that all op amps operate in permanent feedback. These features are obtained with a very simple topology which allows one also to introduce easy predistortion techniques for the finite DC gain of the op amps. The biquad building block is capable of realizing any second-order transfer functions, including those which are obtained using the exact bilinear transformation. Sensitivity performance results of Monte Carlo simulations are given and compared to another well-established biquad topology.<>