A high-Q bandpass fully differential SC filter with enhanced testability

Abstract

This paper presents a low-cost testing approach for switched-capacitor filters. A design for testability (DfT) methodology is discussed, and a system-level architecture is proposed providing capabilities for an off- and on-line test as well as a builtin self-test (BIST). To prove the feasibility of this approach, it has been applied to a sixth-order high-Q bandpass switched-capacitor (SC) filter. The benefit is a significant testability enhancement without degrading filter behavior. Experimental results from a silicon prototype are also presented.