Test input vectors for supply current testing of TTL combinational circuits

Abstract

Test input vectors for ISCAS-85 benchmark circuits are derived, with which single faults of each signal line in the TTL combinational circuits can be detected by their quiescent supply currents. Also, they are compared with the vectors for fault detection methods on the primary output logic values. It is shown that by detecting faults with supply currents of TTL circuits, smaller size of test inputs can be derived for most of the circuits than fault detection methods based on the primary output logic values, and also, if both the output logic values and the supply current are used for detecting faults, the number of the test inputs can be reduced.<>