An approximate noise computation for general integrator-based SC filters

An approximate measure for the noise performance of integrator-based SC (switched capacitor) filters of general order n is developed. The measure is dependent on SC-design parameters such as capacitor ratios and capacitance levels, but not on technology-dependent parameters describing the switches and amplifiers. A simple and explicit closed-form expression for this approximate noise measure is derived and compared with more complex-and accurate-measures. The comparison demonstrates extraordinary accuracy for the approximate noise computation presented. An important application for this noise measure is in the optimization of integrator-based SC filters; it is used in the computer-aided design of sensitivity- and noise-optimized SC filters