Integrated circuits are a very special and important topic for digital electronics. Digital Electronics is related to 0 and 1 . Using 0, 1 only every analog waveform is digitally represented.
The simple definition of the integrated circuit is a miniature low-cost electronic circuit that consists of both active and passive elements fabricated on single-crystal silicon. The integrated circuit is made of semiconductor material. Integrated circuits are divided based on many parameters. They are
- Based on application.
- Based on Technology.
- Based on the Integration level.
Based on the Application
There are two types of integrated circuits based on the application. They are
1. Linear integrated circuits: Linear integrated circuits have an infinite number of continuous input and output states. Linear integrated circuits are again divided into
- General-purpose: Examples: IC555
- Special purpose: Examples: LM380 for audio amplification
2. Digital integrated circuits: Digital integrated circuits have a finite number of discrete input and output states.
Based on Technology
The flow diagram of the Integrated circuit based on the technology is given below.
Integrated Circuit
Types of Integrated Circuit
There are two types of integrated circuits based on technology. They are
1. Monolithic technology: Monolithic circuits are acts as full circuits designed on a single piece of silicon or any semiconductor. Examples: Operational amplifier IC741.
There are two types of monolithic technology. They are:
-
Bipolar: In the Bipolar saturated logic families the bipolar transistor are used as the main device. It is used as a switch and operated in the saturation or cutoff region. TTL is an example of saturated bipolar logic the bipolar transistor are not driven into hard saturation. This increase the speed of operation. So the unsaturated bipolar IC’s such as schottky TTL and ECL compared to TTL.Again bipolar is divided into two types. They are:
- PN junction isolation
- Dielectric isolation
-
Unipolar: The MOS family fabricates MOS field affect transistor(MOSFT’s). In the MOS category there are three logic families namely, PMOS, NMOS, CMOS . PMOS is oldest and slowest types, NMOs is used for the LSI(Large Scale Integration) field for microprocesses memories CMOS – which uses a push- pull arrangement of n- channel and p-channel MOSFET’s is extensively used where low power consumption is needed such as in pocket calculator. Unipolar is again divided into two types. They are
- FET
- UJT
2. Hybrid technology: Hybrid technology has a ceramic substrate that carries many silicon chips. It can also use mixed technology like GaAs chips along with silicon chips.
Based on Integration Level
There are five types of integration levels. They are tabled below.
| Level of integration | Number of devices |
|---|---|
| Small-scale integration | less than 100 |
| Medium-scale integration | 100 to 10,000 |
| Large scale integration | 10,000 to 1,00,000 |
| Very large scale integration | 1,00,000 to 10,00,000 |
| Ultra large-scale integration | greater than 10,00,000 |
Dimensions of the integrated circuit based on integration level:
Small Scale Integration
- For small-scale integration, the length should be 1mm
- For small-scale integration, breadth should be 1mm
- For small-scale integration, the height should be 0.5mm
Medium Scale Integration
- For medium-scale integration, the length should be 4mm
- For medium-scale integration, breadth should be 4mm
- For medium-scale integration, the height should be 0.5mm
Large Scale Integration
- For large-scale integration, the length should be 10mm
- For large-scale integration, breadth should be 10mm
- For large-scale integration, the height should be 0.5mm
Very-Large-Scale Integration
- For a Very large scale integration length should be 10mm
- For Very large scale integration breadth should be 10mm
- For Very-large-scale integration, the height should be 0.5mm
Ultra Large-Scale Integration
- For Ultra large scale integration length should be 10mm
- For Ultra large-scale integration breadth should be 10mm
- For Ultra large-scale integration height should be 0.5mm
Digital logic Families in the Integrated Circuits
1. TTL: TTL stands for Transistor transistor logic. In Transistor-Transistor logic, logic gates are built around transistors which is why it is called TTL. The basic gate in the TTL circuit is the NAND gate. There are many types of TTL families. They are
- Standard TTL.
- Speed TTL
- Low Power TTL.
- Schottky TTL.
- Low Power Schottky TTL
- Advanced Schottky TTL
- Advanced Low Power Schottky TTL
- Fast Schottky
2. ECL: ECL stands for Emitter coupled logic. In this digital logic family Emitters of the transistors are coupled and also those transistors are operated in more active regions than saturation regions. The basic gate in the ECL circuit is OR and NOR gates.
3. MOS: MOS stands for Metal Oxide Semiconductor. This digital logic family is designed simpler with low power. The basic gate in the MOS circuit is the NAND gate. There are two types of MOS circuits. They are.
- NMOS: In nmos, there is more number of n-type areas than p-type.
- PMOS: In pmos, there is more number of p-types areas than n-type.
4. CMOS
CMOS stands for Complementary metal-oxide-semiconductor. In CMOS basic gates are NOR and NAND. CMOS is designed with a combination of PMOS and NMOS. There are some types of CMOS. They are.
- Static CMOS
- Pseudo-nMOS
Advantages of the Integrated Circuit
- The integrated circuit takes very low power.
- Integrated Circuit has high reliability.
- Integrated Circuit is available at a low cost.
- The integrated circuit is operated at high speed.
Disadvantages of the integrated Circuit
- Transformers and Inductance have no concept of the Integrated circuit.
- If one component of the integrated circuit fails then the whole circuit is replaced.
- Integrated circuits are not flexible.
Applications of the Integrated Circuit
- In memory devices, the integrated circuit is used.
- In microwaves, the integrated circuit concept is used.
- In temperature sensors integrated circuit concept is used.
- In Timers, counters integrated circuit is used.