Patent ID: 6930500

Claim:
A method for testing an integrated circuit comprising a power supply voltage, a ground, at least one pair of electrical nodes located in a section of the circuit to be tested, and at least one fault injector for completing an electrical path between the pair of electrical nodes; wherein the fault injector comprises a gate for operating the fault injector in an on-state or off-state condition, and a source node and a drain node for completing an electrical path between the pair of electrical nodes; the method comprising the steps of: (a) introducing an electrical short between the pair of electrical nodes by supplying the gate with a gate voltage exceeding a threshold voltage that causes the fault injector to operate in an on-state condition; (b) adjusting the frequency and length of time of the electrical short to simulate various physical defects that occur in integrated circuits by adjusting the gate voltage to a voltage ranging from about the threshold voltage to about the power supply voltage; wherein, if the gate voltage is increased, the resistance between the electrical nodes decreases; and if the gate voltage is decreased, the resistance between the electrical nodes increases; and (c) monitoring quiescent current levels in the integrated circuit using a built-in current sensor; wherein: (d) when the gate voltage is less than about the threshold voltage, the fault injector remains in the off-state condition, and the integrated circuit performs normal operations without electrical interference; and when the gate voltage is between about the threshold voltage and about the supply voltage, the gate is switched to the on-state condition and the fault injector causes an electrical short between the electrical nodes such that the quiescent state current exceeds a predetermined reference current; if the quiescent state current exceeds the reference current, the built-in current sensor signals that a defect exists; and if the quiescent state current is less than the reference current, the built-in current sensor signals that no defect exists.