Efficient noise analysis of ideal switched-capacitor networks with experimental verification

An exact method is outlined for computing the noise power spectral density (PSD) in "nearly" ideal switched capacitor networks (SCNs). Explicit formulas are presented for both white and 1/f input noise. The 1/f noise source is handled directly in the formulation without having to approximate its PSD using a noise shaping filter. The technique avoids computing eigenvalues or matrix exponentials, as well as solving bilateral matrix equations. The proposed formulation is based on the charge state variable characterization. Thus, it is directly adaptable to the ideal SCN simulator such as SWITCAP. The formulation is presented by emphasizing on an operational amplifier (opamp) modeled by finite gain and pole frequency, and its input-referred noise PSD. An experiment is presented to demonstrate the validity of the proposed formulation.