An Automatic Offset Compensation Sense Amplifier Featuring High Readout Reliability for SRAM

With technology nodes aggressive scaling down, offset voltage has been emerging as one of the critical readout reliability issues of SRAM. This paper proposes a method named automatic compensation sense amplifier (ACSA), to tackle it by identifying the direction of offset and compensating automatically. This method obtains and stores the offset direction through one-time sensing, and then auxiliary transistors in corresponding branches are turned on for current compensation. The circuit implementation of the method is evaluated with SMIC 55-nm technology, operated at a supply voltage of 1.2 V. The proposed ACSA achieves a 66.19% reduction in voltage offset compared to conventional Current Launch SA (CLSA), and a 30.6% reduction compared to conventional Voltage Launch SA (VLSA).