Novel bootstrapped CMOS differential logic family for ultra-low voltage SoCs

Abstract

This paper describes novel bootstrapped CMOS logic family operating at ultra-low supply voltages. The proposed logic family provides better switching performance than conventional bootstrapped logic family by isolating the bootstrapping circuit from timing-critical signal paths. The logic family also minimizes area overhead due to the bootstrapping circuit by adapting a differential structure having a single bootstrap capacitor shared between complementary outputs. Multi-input XOR/XNOR gates and 64-bit adders were designed in 0.18um CMOS process as test vehicles for assessing the performance. Comparison results indicate that the power-delay product of the proposed logic family is improved by up to 67% compared to conventional differential logic circuits at the supply voltage ranging from 0.5V to 0.8V.