Testability Structure for Continuous Time Analog Filters in Mixed-signal Devices

This paper discusses the importance and difficulties associated with testing analog circuits in general and those residing within mixed-signal circuits in particular. It proposes a tested method that is not specification oriented. The method is based on the excitation of the circuit-under-test with a pseudo random binary sequence and the subsequent analysis of the captured response. The fault detection capabilities of the test and data analysis methods are demonstrated by applying them to a continuous time filter circuit operating in the mid-band frequency range. The paper then explores the impact of the test sequence length on the detectability of faults. It also proposes a design for testability structure that supports the proposed test technique.