Abstract
A sub-threshold design could provide a compelling approach to power critical applications. An exponential relationship exists, however, between the delay and the threshold voltage, that makes this design-time timing closure extremely difficult, if not impossible, to achieve. Several previous studies were focused on the technique of body biasing during post-silicon tuning for delay compensation. But they were mostly for super-threshold designs where spatially correlated L eff variation dominates. They cannot be applied directly to sub-threshold designs in which purely random threshold voltage variations dominate. These works also assumed multiple body biasing voltage domains and multiple body biasing voltage levels, which involve significant design overhead. The problem of selective body biasing for post-silicon tuning of sub-threshold designs is examined in this paper. The possibility of using only one body bias voltage domain with a single body bias voltage is explored. The problem was formulated first as a linearly constrained statistical optimization model. The adaptive filtering concept from the signal processing community was then adopted so that an efficient, yet novel, solution could be developed. Using several 65 nm industrial designs, experimental results suggest that, compared with a seemingly more intuitive approach, the proposed approach can improve the pass rate by 57% on average with similar standby power and the same number of body biasing gates. This approach can reduce the standby power, on average, by 84%, with a 20% pass rate loss, more than the approach to bias all the gates.
Recommended Citation
H. Geng et al., "Selective Body Biasing for Post-silicon Tuning of Sub-threshold Designs: An Adaptive Filtering Approach," IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems, vol. 34, no. 5, pp. 713 - 725, article no. 7036117, Institute of Electrical and Electronics Engineers, May 2015.
The definitive version is available at https://doi.org/10.1109/TCAD.2015.2401552
Department(s)
Electrical and Computer Engineering
Keywords and Phrases
Adaptive filtering algorithm; body biasing; sub-threshold
International Standard Serial Number (ISSN)
0278-0070
Document Type
Article - Journal
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2024 Institute of Electrical and Electronics Engineers, All rights reserved.
Publication Date
01 May 2015
