A Compact Hybrid Current/Voltage Sense Amplifier With Offset Cancellation for High-Speed SRAMs

摘要

A hybrid current/voltage sense amplification scheme is proposed for high speed SRAMs. The scheme includes an offset cancellation technique which makes it robust against the current sense amplifier (CSA) mismatch. The offset cancellation allows for fast open loop operation of the differential CSA. A fourfold reduction of the cell access time is achieved compared to the conventional scheme under similar cell current and bitline capacitance. Thanks to its automatic turn off nature, the proposed CSA incurs zero static power without an auxiliary turn off circuit. The reduction of the charge redistribution on the bitlines offers a low bitline dynamic power consumption as well. In this work, the proposed scheme is rigorously analyzed and compared to the conventional scheme. The analysis is verified using circuit level simulations and compared to the conventional scheme as a reference analytically and using simulations.