Low-power LSI Circuit Technologies for Portable Terminal Equipment


IEICE TRANSACTIONS on Electronics   Vol.E78-C    No.12    pp.1655-1667
Publication Date: 1995/12/25
Online ISSN: 
Print ISSN: 0916-8516
Type of Manuscript: Special Section INVITED PAPER (Special Issue on Low-power Analog, Digital LSIs and ASICs for Multimedia)
low voltage,  low power,  portable terminal equipment,  multi-threshold CMOS,  

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This paper surveys trends in and prospects for low power LSI circuits technologies for portable terminal equipment, in which low-voltage operation of LSIs will be emphasized because this equipment will be battery-powered. Since this brings about serious operation speed degradation of LSIs, however, it will become more and more important how to operate them faster under low-supply voltage. We propose two new circuit techniques that make it possible to operate LSIs at high speed even when the supply voltage is very low (1-2 V corresponding to one or two battery cells). The new low-voltage RF LSI circuit technique, developed using silicon bipolar technology and using a novel current-folded mixer architecture for the modulator, result in a highly linear modulator that operates at 2 V. Its power consumption is less than 2/3 that of previously reported ICs. And for a low voltage baseband LSI we propose the multi-threshold CMOS (MTCMOS) technique, which uses two sets of threshold-voltage levels so that the LSI can operate at high speed when driven by a 1-V power supply. The multi-threshold CMOS architecture enabled us to create LSIs that operate faster than conventional CMOS circuits using high-threshold-voltage MOSFETs. When operating with a 1-V power supply, our LSIs are three times faster than the conventional ones.