Ttl/Vtl DELTA Current Fault-Detection Method
Original Publication Date: 1985-Jun-01
Included in the Prior Art Database: 2005-Feb-18
The following method, utilizing the analog-to-digital test circuit shown in the figure, allows the detection of heating and propagation delay faults caused by errant impedances between active transistor collectors and the collector voltage supply (VCC)in semiconductor logic chips. This detection of defective semiconductor junctions is accomplished at the static test level, saving costly hours of burn-in or run-in time previously required to isolate such defects. This will decrease the defect rate of installed components in the field by removing defects that normally would not become evident until the circuits were operating for a lengthy time after installation in the final product. This method is applicable to several logic families. Brief test algorithm segment: 1. Pattern test the gate (7408 Totem Pole) 2.