Design of an Analog Fault Model for CMOS Switched Capacitor Low Pass Filter

In this paper an analog fault model for a CMOS switched capacitor low pass filter is tested. The switched capacitor (SC) low pass filter circuit is modularized into functional macros. These functional macros include OPAMP, switches and capacitors. The circuit is identified as faulty if the frequency response of the transfer function does not meet the design specification. The signal flow graph (SFG) models of all the macros are analyzed to get the faulty transfer function of the circuit under test (CUT). A CMOS switched capacitor low pass filter for signal receiver applications is chosen as an example to demonstrate the testing of the analog fault model. The responses of the CUT are simulated using MENTOR GRAPHICS tool with 0.13 μm technology.