Page 1141 - Basic Electrical Engineering

With ICs, electronic circuits and components are becoming smaller and
less expensive. Modern electronics using ICs find applications in mobile
communication, satellite and aerospace communication, high-speed

computers, home appliances and in automatic control systems. Electronics
using ICs are becoming the brains and nerves of our complex society.

TTL 74 series is the most widely used family of digital ICs in the SSI and
MSI categories. Fig. 17.18 shows a standard TTL inverter circuit. It contains

several bipolar transistors, and hence the name TTL (transistor–transistor
logic) is given.

Table 17.2 Integrated Circuits with Their Level of Complexity

Approximate number of
Complexity Typical products
gates per chip
Small-scale integration (SSI) Less than 12 Logic gates, flip-flops

Medium-scale integration (MSI) 12 to 99 Counters, multiplexers, adders

8 bit microprocessors, ROM,
Large-scale integration (LSI) 100 to 9999
RAM
16 bit and 32 bit microprocessors,
Very Large-scale integration
10,000 to 99,999 sophisticated computer
(VLSI)
peripherals

Ultra large-scale integration 64 bit microprocessors, real-time
100,000 or more
(ULSI) image processing