| Sense Amplifier(SA),as the key design in SRAM circuit,has the function of detecting the small voltage difference between the bit lines and amplifying it into circuit-recognizable logic signal.It determines the SRAM’s reliability,stability and power consumption during the reading operation.With the improvement of semiconductor technology,the integration of chip circuit is more precise,but it also brings some disadvantages.Especially,the problem of threshold voltage deviation caused by Random Dopant Fluctuation(RDF),it makes a great impact on the sense amplifiers and other SRAM internal modules.In this paper,the common SRAM amplifier and amplifier timing control circuit is introduced in detail,and the problem of offset voltage of the sensitive amplifier is brought out.By analyzing the causes of the offset voltage,the influence of the offset voltage and the future development trend,we can conclud that the problem of voltage offset is an important question faced by IC designers.At the end of this paper,the traditional sense amplifier is optimized,and the Self-Activated Body-biased Sense Amplifier(SABBSA)is proposed.This amplifier not only can amplify the potential difference according to the actual situation of the bit line swing,thus solving the problem that the traditional amplifier turn-on signal does not match with the actual bit line discharge;And the threshold voltage offset compensation circuit is designed in the critical path of the amplifier to make up for the traditional self-starting the critical path of the amplifier sensitivity defects.By Monte Carlo simulation under TSMC 65nm,SABBSA can reduce the probability of occurrence of read-time fault and reduce the influence of offset voltage effectively. |
