UNDERGRAD Thesis

DESIGN AND ANALYSIS OF ADIABATIC VLSI CIRCUITS

Submitted by: Chamak Ganguly, Saeed Hossen Rakib, Ariful Islam, Farhana Tasnim Aumio

Supervisor: Dr. Satyendra Nath Biswas

In our day-to-day life, power and energy consumption of our used devices have become very important. Due to the mass use of electronic devices, it has become important for longer-lasting batteries which means the size of the battery increases and becomes heavier. On the contrary, if the size decreases then various problems arise. Low scale battery means a low

power supply has to be given which means the threshold voltage of the transistors has to decrease which in turn causes problems like sub-threshold leakage current. The device needs to be velocity saturated and also the threshold voltage becomes more reactive with the change of temperature. Also due to the lower voltage supply, gate-oxide needs to become thinner causing gate leakage and power dissipation.As a result, various power reduction techniques have come forward. Techniques like multi threshold devices (MTCMOS), variable multi threshold devices (VTCMOS), and dynamic

threshold devices (DTCMOS). Also scaling of devices has been used. Out of these techniques, one technique was to use time varying supply voltage instead of the conventional constant voltage supply. With this, the term Adiabatic was introduced for using low power devices.

In this thesis paper, various adiabatic circuits have been explored. And also, a proposed adiabatic circuit has been shown for ultra-low power dissipation.