TESTING ANALOG AND MIXED-SIGNAL INTEGRATED-CIRCUITS USING OSCILLATION-TEST METHOD

A new low-cost test method for analog integrated circuits, called the oscillation test, is presented, During the test mode, the circuit unde r test (CUT) is converted to a circuit that oscillates, Faults in the CUT which deviate the oscillation frequency from its tolerance band ca n be detected. Using this test method, no test vector is required to b e applied, Therefore, the test vector generation problem is eliminated , and the test time is very small because only a single output frequen cy is evaluated for each CUT, The oscillation frequency may be conside red as a digital signal and therefore can be evaluated using pure digi tal circuitry, These characteristics imply that the oscillation-test s trategy is very attractive for wafer-probe testing as well as final pr oduction testing, In this note, the validity of the proposed test meth od has been verified throughout various examples such as operational a mplifiers, amplifiers, filters, and analog-to-digital converters (ADC' s). The simulations and practical implementation results affirm that t he presented method assures a high fault coverage.