Analysis and comparison of XOR cell structures for low voltage circuit design

Abstract

The performance of standard cells has a strong impact on the performance of a circuit synthesized with the cells. Although a complementary CMOS logic is usually used in the standard cells, it is known that a pass transistor logic can improve the performance of a circuit with a smaller area in some cases. We evaluate different types of XOR cells in different voltage conditions. Results show that the dual pass transistor XOR has a better performance than the complementary CMOS XOR in 0.6V operation, while the complementary CMOS XOR has a better performance in 1.2 V operation. More specifically, the area and the power consumption of a benchmark circuit composed of the dual pass transistor XOR can be reduced by 24% and 35%, respectively, compared to those of the same circuit composed of the complementary CMOS XOR in 0.6V operation.