Teknik Digital - What is Digital IC ?

DIGITAL  IC

What is ic ?

An integrated circuit or monolithic integrated circuit (also referred to as an IC, a chip, or a microchip) is a set of electronic circuits on one small plate ("chip") of semiconductor material, normally silicon. This can be made much smaller than a discrete circuit made from independent components.

Integrated circuits are used in all electronic equipment today and have revolutionized the world of electronics. Computers, mobile phones, and other digital home appliances are now inextricable parts of the structure of modern societies, made possible by the low cost of producing integrated circuits.

Plugging ic in circuit board

IC's are come in several shapes and sizes. Most common size are 4, 8, 14, 16, 18 or 20 pin dual in line (dil) chips.

IC's can be soldered directly into printed circuit boards, or may plug into sockets which have already been soldered into the board. We suggest to use the ic’s socket before soldering,then plug the ic after soldering process finished.

When soldering, ensure that the IC (or the socket) is the correct way round and that no pins have been bent underneath the body. Bent pins may influence the ic’s function. It may cause error in yhe circuit.

When fitting new ic’s on the circuit board , two pins at the same line still have wide range. It is often necessary to bend the pins in slightly, in order to fit it into the board (or socket).

Some IC's are damaged by the static electricity which most people carry on their bodies. They should be stored in conductive foam or wrapped in tin foil.  When handling them, discharge yourself periodically by touching some metalwork which is earthed(grounded), such as a radiator or other grounded metal.

Solder two diagonally opposite pins (say pin 1 and pin 5 in the diagram below) and check that the IC is flat on the board before soldering the rest. If it is not flat then reflow the solder on the two pins pushing the IC flat. When satisfied, solder the remaining pins.

Take care when removing faulty IC's from pcb's. You may damage a circuit board when carelessly removing a 20p IC. If the leads are bent over onto the circuit board, and you try to lift them while any of the solder is still adhered, the pad comes off. If you work carefully, suck all of the solder off, and make sure the lead is not adhered to any part of the pad, you won't have this kind of problem.

Example of IC ‘s logic gate

Definition

A Logic AND Gate is a type of digital logic gate that has an output which is normally at logic level "0" and only goes "HIGH" to a logic level "1" when ALL of its inputs are at logic level "1". The output state of a "Logic AND Gate" only returns "LOW" again when ANY of its inputs are at a logic level "0". In other words for a logic AND gate, any LOW input will give a LOW output.

The logic or Boolean expression given for a logic AND gate is that for Logical Multiplication which is denoted by a single dot or full stop symbol, ( . ) giving us the Boolean expression of:  A.B = Q.Then we can define the operation of a 2-input logic AND gate as being: "If both A and B are true, then Q is true"

Some tips to keep the ic :

- Keep the ic’s in safe location ,flat place is better and Far from heavy things.
- Put the ic’s on dry place . You may plug it in a sterofoam to avoid bent pins.
- No over heating or over voltage. It cause fatal damage inside the ic.
- Make sure that it far from children . They always want to eat everything in this world .