On-chip compensation control for voltage regulation
Manufacturing and/or operational variations that affect performance of an integrated circuit (IC) are at least partially compensated for, by determining the magnitude of these variations and providing one or more corresponding control signals to a voltage regulator, which, responsive thereto, increases or decreases the magnitude of the output voltage. The output voltage of the voltage regulator is typically provided to a power supply node of the IC. Similarly, the output of the voltage regulator may be provided to a substrate portion of the IC, so as to provide a substrate bias that is variable in response to changes in the performance of the IC. In various embodiments, a determination of the magnitude of the variations is made by comparing the performance of a digital delay circuit or a ring oscillator to a reference clock; speed characterization of the IC may be obtained from the voltage regulator control signals; and information regarding reliability degradation of the IC may be obtained from the control signals that are generated for control of the voltage regulation circuitry.
1. An apparatus, comprising:
a first circuit, disposed within an integrated circuit, the first circuit having a first positive supply rail coupled to an output terminal of a regulated power supply, the first circuit having at least one operating characteristic that is dependent upon the magnitude of a voltage that is supplied at the output terminal of the regulated power supply, the first circuit operable to provide a first signal indicative of the at least one operating characteristic at a first output terminal; and
a second circuit coupled to the first output terminal of the first circuit, the second circuit adapted to receive a reference clock signal, the second circuit further adapted to compare the first signal and the reference clock signal and to provide a control signal for controlling the magnitude of the voltage that is supplied at the output terminal of the regulated power supply;
wherein the regulated power supply, responsive to the second signal, increases or decreases the magnitude of the voltage that is supplied at the output terminal of the regulated power supply, such that at least one operating characteristic of the first circuit is modified to be within a predetermined range; and
wherein the regulated power supply is disposed external to the integrated circuit, the integrated circuit includes circuitry, disposed in the integrated circuit, in addition to the first and second circuits, and the output terminal of the regulated power supply is further coupled to supply power to the additional circuitry.
2. The apparatus of claim 1 , wherein the first circuit comprises an inverter chain.
3. The apparatus of claim 1 , wherein the first circuit comprises a ring oscillator.
4. The apparatus of claim 1 , wherein the second circuit is disposed within the integrated circuit.
5. The apparatus of claim 1 , wherein the at least one operating characteristic of the first circuit is leakage current.
6. The apparatus of claim 1 , wherein the integrated circuit is a field programmable gate array.