Patent ID: 7977998

Claim:
An integrated circuit comprising: one or more level shifter modules, each including: one or more level shifter circuits, each coupled to receive a first supply voltage and a second supply voltage, and wherein each level shifter circuit is configured to receive an input signal that is referenced to the first supply voltage and to generate an output signal that is referenced to the second supply voltage and wherein the output signal corresponds to the input signal; and detection logic coupled to each of the level shifter circuits and configured to detect an output value of each of the one or more level shifter circuits; and a control circuit coupled to the one or more level shifter modules and to a reference voltage supply source, and configured to iteratively change one of the first supply voltage and the second supply voltage responsive to a control signal while the input signal is provided to the one or more level shifter circuits; wherein the detection logic is further configured to capture the output value upon each change in the first supply voltage and each change in the second supply voltage.