Detection of faults in ECL storage elements

Bipolar emitter-coupled logic (ECL) devices can be fabricated at very high densities and much lower power consumption. Analysis of faulty behavior of ECL storage elements shows they exhibit stuck-at behavior, loss of complementarity, delay faults and enhanced current being drawn by the device. Detection of the above behavior under faults using logic monitoring requires careful and systematic generation of input vectors. Testing for delay faults is even more difficult. A fault causing a delay fault as well as enhanced power supply current is shown. A current monitor for the detection of the enhanced power supply current is presented.