PROPOSED SRAM CELL USING LOW POWER SCHMITT TRIGGER IN SUBTHRESHOLD REGION WHICH ADAPTS ITS OWN THRESHOLD

In 1950, an American biophysicist and polymath Otto Schmitt coined the term ‘Biomimetics’ (imitation of nature element, systems, models for the purpose of solving complex problems of the human). Proceeding on the same concept, finally he developed the Schmitt Trigger by studying the nerves in squid, attempting to engineer a device that replicated the nerve propagation’s biological system during his doctoral research. Many researchers proposed the numerous designs, advantages and implementation of Schmitt Trigger for different applications. This paper reveals a detail review of each circuit illustrated in literature for last two decades in terms of their merits and demerits. Section 1 gives brief illustration of history, properties and advancement of Schmitt Trigge,. Section2 comprises merits, demerits and application of Schmitt Trigger. Section 3 gives detailed review about threshold adaption by Schmitt trigger and Section 4 ends with the summary of the review.