具有低失调电压的新型灵敏放大器设计

Design of a Novel Sense Amplifier with Low Offset Voltage

由于器件尺寸越来越小,器件之间的失配越来越严重,由器件失配引起的失调电压对灵敏放大器性能的影响越来越大。针对此情况,根据灵敏放大器的工作原理,提出了一种具有失调电压自调整的灵敏放大器,通过增加校准支路来平衡灵敏放大器两边的放电速度,从而降低失调电压,减小其对灵敏放大器性能的影响。基于SMIC 65 nm CMOS工艺的后仿真结果显示,在电源电压1.2 V、TT工艺角、室温条件下,相比于传统的灵敏放大器,该新型灵敏放大器的失调电压的标准偏差降低了61.9%,SRAM的读关键路径延迟降低了25%。

With the decreasing of device size,the mismatch between devices becomes more and more serious,and the offset voltage caused by transistor mismatch has a significant effect on sense amplifier performance.Based on the operating principle of sense amplifier,a novel sense amplifier with self-calibration character is proposed.The reduction of offset voltage can be realized by two calibrated branches,which were used to balance the discharging current between two storage nodes of sense amplifier.The simulation results show that the standard deviation of offset voltage of the proposed sense amplifier is 61.9%smaller than that of the conventional current latch sense amplifier at 1.2 V supply voltage,TT corner and room temperature in SMIC 65 nm CMOS technology.As a result,the sensing delay of the read critical path is reduced by 25%.