Optimal test-set generation for parametric fault detection in switched capacitor filters

The functional performance of switched capacitor circuits is directly affected by variations in capacitor ratios. We have proposed techniques to accurately measure these capacitor ratios. In this paper we develop an optimal procedure to minimize the number of capacitor ratios that need to be measured while still maintaining the desired fault coverage. We make use of the sensitivity of individual performance specifications to specific capacitor ratios. The procedure has been validated with a number of examples including a first order lossy integrator a second order low-pass filter and sixth order high Q bandpass filter. The procedure developed in this paper can easily be extended to include other switched capacitor circuits.