A low-power ternary content-addressable memory using pulse current based match-line sense amplifiers

This paper presents the design of the pulse current based match-line sense amplifier (PCB-MLSA) for low-power ternary content-addressable memories (TCAMs). In the PCB-MLSA scheme, each matchline in the TCAM is charged with a pulse current and then the voltage development on the matchline is sensed to distinguish between the match case and the mismatch case. In contrast to conventional MLSAs, which regulate the charging current injecting to the matchline based on the match condition during the evaluate phase, the proposed PCB-MLSA does not need to provide additional current to the matchline except the initial pulse current regardless of the match condition. PCB-MLSA achieves power savings by reducing matchline voltage swing and searchline switching activity in the TCAM and employs a positive-feedback network to boost the search speed of the TCAM. Simulation results show that the proposed PCB-MLSA can achieve a search time of 0.418 ns and an energy consumption of 0.194 fJ/bit/search. Compared with the conventional precharge-high MLSA, the positive-feedback MLSA, the stability-based MLSA, and the double positive-feedback MLSA, the proposed PCB-MLSA can reduce the search delay by 62.2%, 12.0%, 60.0%, and 15.9%, respectively, and reduce the energy consumption by 86.2%, 13.8%, 24.2%, and 3.5%, respectively.