Fault detection in resistive ladder network with minimal measurements

Testing of integrated circuits has now become a very important part of the semiconductor industry. Testing alone exceeds the cost of designing and manufacturing. So it is important to device new techniques to reduce the time and effort spent in testing [1]. The basic idea of the work done is to come up with a strategy to identify any fault in a resistive ladder network with minimal measurements, thereby reducing the testing time, efforts and cost [1]. Ideally the whole ladder circuit should act as a single segment and one or two measurements should detect the fault (location and type of fault). But since that is not possible we split up the big ladder network into segments which are as big as possible and at the same time giving good fault coverage. The ladder network was split into segments of different sizes. For each size scenario we analyzed the fault coverage. A detailed analysis for 2-step (4 resistors), 3-step (6 resistors) and 4-step (8 resistors) ladder networks were carried out and the results were found to be in favor of the 3-step ladder.