Factory testing on a production line can uncover several types of device failures. However, certain subtle failures can be masked from test procedures only to be discovered too late, e.g., by the customer. An example of such a failure is a missing bulk capacitor in circuits such as amplifiers, regulators, etc. Such a failure can go undetected at a factory due to the presence of smaller capacitors that have a marginally compensating effect. This disclosure describes techniques to detect missing bulk capacitors on circuit boards by inserting a simulated load resistance and measuring the decay time of an injected test voltage. A missing bulk capacitor is detected by decay times that are much faster than normal or expected.
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Gupta, Puneet and Trehan, Chintan, "Detecting Missing Capacitors by Load Sensing", Technical Disclosure Commons, (March 09, 2020)