A Sense Amplifier Using Resistive Feedback for Offset Compensation

As the size of the dynamic random access memory (DRAM) shrinks, offset voltage caused by transistor mismatch seriously affects the performance of data reading. In this paper, a sense amplifier with resistive feedback (RFSA) and a sense amplifier with common resistive feedback (CRFSA) are proposed to compensate the offset of bit-line sense amplifier (BLSA) in DRAM. In this way, the initial node voltage of the sense amplifier could be set very close to the metastable-point. Simulation results show that the offset voltage is reduced by more than 90% (RFSA) and 70% (CRFSA) compared with the offset mismatch calibration sense amplifier (OMCSA). In addition, under circumstances of different transistor sizes, large bit-line capacitance, temperature changes, etc., RFSA and CRFSA both have excellent performance in offset compensation, thus having a significant advantage in eliminating the effects of process fluctuations on the BLSA offset.