Mathematically assisted adaptive body bias (ABB) for temperature compensation in gigascale LSI systems

Abstract

Process variations and temperature variations can cause both the frequency and the leakage of the chip to vary significantly from their expected values, thereby decreasing the yield. Adaptive body bias (ABB) can be used to pull back the chip to the nominal operational region. We propose the use of this technique to counter temperature variations along with process variations. We present a CAD perspective for achieving process and temperature compensation using bidirectional ABB. Mathematical models are used to determine the exact amount of body bias required optimizing the delay and leakage, and an algorithmic flow that can be adopted for gigascale LSI systems is provided