Ultra-low power 32-bit pipelined adder using subthreshold source-coupled logic with 5fJ/stage PDP

摘要

source-couple logic (STSCL) circuits. Using a simple two-phase pipelining technique, it is possible to increase the activity rate of STSCL gates with negligible additional cost, and hence reduce the total system energy consumption per operation. In the proposed pipelined topology, each STSCL gate is followed by a simple cross-coupled differential pair operating as a state keeper with a very low power consumption and small area overhead. Measurement results on a 32-bit pipelined adder chain fabricated with 0.18 μm CMOS technology show that the proposed approach can achieve a significant reduction in power-delay product (PDP) down to 5 fJ/stage.