Design of a Fault-Injectable Fleischer-Laker Switched-Capacitor Biquad for verifying the Static Linear Behavior Fault Model

Abstract

This paper presents the design of a fully-differential low-pass SC biquad filter that allows injecting the parametric and catastrophic faults to it. The design is for the verification of the static linear behavior (SLB) fault model which covers multiple parametric and catastrophic analog faults of sampled-data systems. The SLB fault model assumes that a circuit under test (CUT) has a fixed z-domain transfer function (TF) template and the faults alter nothing but the coefficients of the TF. To verify this basic assumption, we first retrieve all coefficients of the TF of the fault-injected biquad from the test results of a three-tone test following the diagnosis-after-test (DAT) procedure. Then, we conduct simulations with other stimulus tones and check if the tested responses fit in those predicted by the retrieved TF. Experimental results verify that the fixed TF template assumption holds for all the faults that we injected.