17-11-2012, 02:54 PM
INTRODUCTION TO VLSI
INTRODUCTION TO VLSI.pptx (Size: 251.95 KB / Downloads: 28)
INTEGRATED CIRCUITS TRENDS
An entire circuit is manufactured in a single piece of silicon, first appeared around 1960
At that time only a few simple gates offering primitive logic functions such as not, nand, nor etc. could be accommodated (SSI)
By 1970 MSI circuits with about a thousand transistors appeared
By 1980 LSI circuits of approximately one hundred thousand devices were possible
VLSI
VLSI stands for "Very Large Scale Integration". This is the field which involves packing more and more logic devices into smaller and smaller areas.Thanks to VLSI, circuits that would have taken boardfuls of space can now be put into a small space few millimeters across!
MOORE’S LAW
Gordon Moore: co-founder of Intel
Predicted that the number of transistors per chip would grow exponentially (double every 18 months)
Exponential improvement in technology is a natural trend:
e.g. Steam Engines - Dynamo - Automobile
Choice of Technology
Two distinct types of technology are fabricated in silicon based upon
BJT (Bipolar Junction Transistor)
MOS (Metallic Oxide Semiconductor)