Serial sub-threshold circuits for ultra-low-power systems

This paper explores the use of serial circuits for ultra-low-power sub-threshold systems. A serial system leads to a smaller design and higher utilization, yielding 40% active energy, 15x active power, and 32x leakage power benefits. Further, we show that using a serial system in the sub-threshold regime decreases both active energy and leakage power even at the same speed as a parallel system. This is in sharp contrast to strong inversion, where larger bit widths give lower energy and power for the same delay. We identify the unique properties of sub-threshold operation that creates these differences. Categories and Subject Descriptors B.6.1 [Logic Design]: Design Styles – combinational logic, parallel circuits, sequential circuits. General Terms Performance, Design Keywords Ultra low power, serial systems, bit width, sub-threshold, leakage.

• Type: Conference
• Year: 2009
• Where: ISLPED
• Authors: Sudhanshu Khanna, Benton H. Calhoun
• Keywords: Active Energy, Hardware, ISLPED 2009, Leakage Power, Leakage Power Benefits