Integrated circuits (ICs) are
considered as a foundation of present-day electronics. They are the cornerstones
of most circuits. These are the omnipresent tiny black “chips” which come into
view on just about every circuit board. If you are not some kind of insane,
analog electronics wizard, perhaps you will have at least one IC in each electronics
project you set up, so it is vital to understand them, inside and out.
A collection of electronic components
like capacitors, resistors, transistors- all crammed into a small chip, and
linked with each other to attain a common goal is called an IC. These come in
various sorts and varieties: single-circuit logic gates, voltage regulators,
microcontrollers, op amps, microprocessors, 555 timers, motor controllers,
FPGAs… the list does not end.
We can visualize the tiny black chips
by thinking about integrated circuits. But what does the black box contain? The
actual “substance” to an integrated circuit is a complicated layer of
semiconductor wafers, copper, and other materials, which interlinks to create
resistors, transistors and various components in a circuit. The trimmed and
well-formed amalgamation of these wafers is known as die.
The integrated chip itself is small and
because of this the wafers of semiconductor and layers of copper it consists of
are extremely thin. The interconnections between the layers are immensely complex.
A die of an integrated chip is the circuit in its tiniest allowable form, too tiny
to solder or connect to. The die is packaged, which makes our job of connecting
to the IC effortless. The IC package turns the delicate, tiny die, into the
black chip we’re all familiar with. The small and delicate die is turned into
the black chip (which is familiar to all) by the IC package.
The integrated circuit die is
encapsulated by the package and this package splays the die out into a device
we can more conveniently connect to. Every outward connection on the die is
linked via a small piece of gold wire to a pad or pin on the
package. Pins are the silver, releasing terminals on an IC, which go on to attach
to other parts of a circuit. Pins are what will go on to connect to the rest of
the components and wires in a circuit. For this reason, these are most
important to us.
There are numerous varieties of packages.
Each of them has distinctive dimensions, mounting-types, and/or pin-counts.
Majority of them are DIP, QDIP, SQP, PDIP, SOP, QFP, PLCC, SW, SQL, DPAK, SIP, SOS,
TSOP, FDIP, TO3, TO2205, SOT23, SOT223, PENTAWATT and many more.
Each pin of an IC is unique in the cases
of both location and function and all ICS are polarized. This means the package
has to have some way to convey which pin is which. Maximum ICs use either a dot
or a notch to specify which pin is the first pin. (Sometimes both, sometimes
one or the other).
Once
you know where the first pin is, the remaining pin numbers increase
sequentially as you move counter-clockwise around the chip.
