Adaptive voltage control and body bias for performance and energy optimization

A device for adaptively controlling a voltage supplied to circuitry in close proximity to the device, comprising a processing module and a first tracking element coupled to the processing module. The first tracking element produces a first value indicative of a first estimated speed associated with the circuitry. The device also comprises a second tracking element coupled to the processing module. The second tracking element produces a second value indicative of a second estimated speed associated with the circuitry. The processing module compares each of the first and second values to respective target values and causes a voltage output to be adjusted based on the comparisons. The first and second tracking elements comprise a plurality of transistors, at least some of the transistors selectively provided with a transistor bias voltage to adjust transistor speed.