Test circuit and test method for protecting an IC against damage from activation of too many current drawing circuits at one time

摘要

Power supply connections to an integrated circuit are tested. The power supply connections are connected to a power supply conductor in the integrated circuit. For the test, combinations of current drawing circuits are switched on near the point where the power supply connection under test is connected to the power supply conductor. The current drawing circuits draw a considerable current, so as to cause a detectable voltage drop over the power supply connection, if this connection is operational. Different subsets of the current drawing circuits are activated successively. To prevent that all of the current drawing circuits are switched on at the same time by error, activation of each subset is controlled by a signal indicative of completion of activation of the preceding subset. A respective signal line is provided for each subset, to provide the signal for the subset.