US Patent 10475677 Parallel test structure

An exemplary apparatus includes a testing module connected to, and providing a test voltage to, an integrated circuit containing devices under test. The testing module performs a time-dependent dielectric breakdown (TDDB) test on the devices under test. A decoder is connected to the devices under test and the testing module. The decoder selectively connects each device being tested to the testing module. Efuses are connected to a different one of the devices under test. The efuses separately electrically disconnect each of the devices under test from the test voltage upon failure of a corresponding device under test. Protection circuits are connected between the efuses and a ground voltage. Each protection circuit provides a shunt around the decoder upon failure of the device under test.