SUPPLY VOLTAGE COMPENSATION FOR AN INPUT/OUTPUT DRIVER CIRCUIT USING CLOCK SIGNAL FREQUENCY COMPARISON

摘要

A process and temperature variation operating condition that is globally applicable to an integrated circuit die is sensed in a core circuit region to generate a global process and temperature compensation signal. A voltage variation operating condition that is locally applicable to an input/output circuit within a peripheral circuit region of the integrated circuit die is sensed to generate a local voltage compensation signal. More specifically, the localized voltage operating condition is generated as a function of a measured difference in frequency between a first clock signal generated in the peripheral circuit region in response to a supply voltage subject to voltage variation and a second clock signal generated in the core circuit region in response to a fixed bandgap reference voltage. The operation of the input/output circuit is then altered in response to the global process and temperature compensation signal and in response to the local voltage compensation signal.