US Patent 7151417 System and method for characterizing a potential distribution

An apparatus for characterizing an operating parameter in an integrated circuit, in accordance with one embodiment of the present invention, includes a voltage potential module, a plurality of distribution systems and a plurality of ring oscillator modules. Each ring oscillator module is coupled to the voltage potential module by a respective distribution system. Each ring oscillator module generates an oscillator signal as a function of the voltage potential and a voltage drop caused by the respective distribution system. The characterization of the operating parameter may be extrapolated from the difference in the operating frequencies of the ring oscillator modules.