Author: Soft Electro Mech
Integrated Circuits (ICs)

Integrated Circuit (IC) is also called as Chip or Microchip or Silicon Chip,
An IC can do following functions in single or combination of counter, timer, amplifier, oscillator, memory, ADC, DAC , arthematics etc. A microprocessor or a micro-controller also falls under IC catagory.
As the name suggests, An Integrated Circuit (IC), is a summation of electronic elements of a functional circuit available in small package.
In other words, IC is a small semiconductor wafer, usually made of silicon, on which multiple tiny transistors, resistors, diodes, capacitors etc., are fabricated to form a useful or functional circuit, which is enclosed in a plastic or ceramic material with the connecting pins on its periphery (or surface).
The complexity and functionality of an IC depends on the number of transistors and associated electronic components used on a silicon wafer. The following is the types of integration and associated number of transistors used in the IC.
| Integration | Description | Number of Transistors in IC |
| SSI | Small Scale Integration | 1 to 10 |
| MSI | Medium Scale Integration | 10 to 500 |
| LSI | Large Scale Integration | 500 to 20,000 |
| VLSI | Very Large Scale Integration | 20,000 to 1,000,000 |
| ULSI | Ultra Large Scale Integration | above 1,000,000 |
ICs are available in various packages with specific name.ย The package name indicates the size, shape, position of pins, pin out format etc.
Some package names are listed as :
DIP / DIL = Dual In Line Package.ย Mostly through hole type package used to put on one side of the PCB ( Printed Circuit Board ) and solder on the opposite side of the PCB.
SIL / SIP = Single In Line Package.
PDIP = Plastic Dual In Line Package.
CDIP = Ceramic Dual In Line Package.
SO / SOICย / SOP : Small-Outline Integrated Circuitย
QIP / QIL = Quadraple In Line Package.
SMT = Surface Mount Technology package.ย The IC is placed on the PCB and solder on the track of same side of the PCB. SOJ , SOIC , LQFP, QFN, MLF, QFP, MQFP are some variants of SMT ICs, having various types pin outs.
LQFP = Low-profile Quad Flat-Package is SMT IC.
TQFP = Thin Quad Flat-Package (having leads) is SMT IC.
TQFN = Thin Quad Flat No-lead
PLCC = Plastic Leaded Chip-Carrier
CLCC = Ceramic Leadless Chip-Carrier
QFN/MLF = Quad flat No-leads package. Also called as Micro Lead Frame.
QFP = Quad Flat Package.
MQFP = Metric Quad Flat Package.
TO-220 = Through-hole plastic package with three leads attached with a metal heat sink tab with hole on top.
SOT-23 / SOT-223 = Small Outline Transistor Package is SMT IC, having three pin-outs.ย
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4 pin DIP IC. Normally used for Infra Red (IR) Transmitter (TX) Receiver (RX) pair.
eg :
