Page 105 - Understanding Automotive Electronics

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3 ELECTRONICS FUNDAMENTALS

INTEGRATED CIRCUITS

By using integrated circuit technology, all of the counters, registers, and
binary-to-decimal converters are produced at the same time on a tiny piece of
silicon semiconductor material by the techniques of photolithography
(photographic printing) and diffusion (modifying one material by combining it
with another using high temperature). This is the heart of integrated circuit
technology. The results are very small, high-performance circuits that use very
low power and have a high reliability.
The earliest ICs appeared about 1960 and had relatively few gates,
typically on the order of 10 to 12. Those devices were known as small-scale
integration (SSI) integrated circuits. By 1970, medium-scale integration (MSI)
ICs were available; they had on the order of 1,000 gates. The evolution of
technology continued through phases of large-scale integration (LSI) ICs to
very large scale integration (VLSI) ICs that had 5,000 or more gates.
Digital circuits are now One of the important consequences of IC technological progress has been
available as electronic that digital circuits have become available (in IC form) as electronic systems or
systems or subsystems subsystems. That is, the functional capability of digital circuits in single IC
packaged as ICs. packages, or chips, has spectacularly increased in the past 30 years. One of the
important digital systems that is available as an LSI IC is the arithmetic and
logic unit (ALU).
Figure 3.11 is a sketch of a typical ALU showing the various connections.
This 4-bit ALU has the capability of performing 16 possible logical or

Figure 3.11
ALU Circuit
Configuration

FPO

92 UNDERSTANDING AUTOMOTIVE ELECTRONICS