A Simplified Model for Passive-Switched-Capacitor Filters With Complex Poles

This brief demonstrates a method to realize complex conjugate poles using passive-switched-capacitor networks. In addition, a simplified continuous-time model will be introduced so that accurate transfer functions and output noise can be obtained without the need for complicated charge-balance equations and thereby allow a better intuitive understanding of these structures. The developed theory is demonstrated through the design of a second-order low-pass Butterworth biquad with applications intended in the design of wireless RF receivers.