Classification of integrated circuits

Classification of integrated circuits

Depending upon the functional utility, the integrated circuits are classified as linear ICs and digital ICs. From the point of view of structural considerations, ICs can be divided as monolithic ICs, thick-thin film ICs and hybrid ICs. The monolithic ICs are most common type of IC. In the monolithic ICs, all the active and passive components alongwith their interconnections are manufactured on a single silicon chip. In general, the monolithic ICs has power limitations ; hence they are preferred only in low power applications.

In general, thick-thin film ICs are used to produce only the passive elements. The film technology is used to develop thick-thin film ICs. By combining the passive elements with pre-fabricated active components. Generally the film circuits are made by depositing various film capacitors and resistors on a separate substrate such as glass or ceramic used as passive substrate. And then the pre-fabricated active components are added into the substrate. The thick film technology is easy and inexpensive. The thin film technology produces components with greater presicion, but it is expensive as compared with the other technology.

For high power applications, hybrid ICs are used. Hybrid ICs combine two or more monolithic ICs in one package. They may combine monolithic ICs with thick-thin film circuits.

On the basis of the active devices used, the ICs are classified as bipolar ICs and unipolar ICs. The bipolar ICs use bipolar junction transistors (BJTs), while the unipolar ICs use field effect transistors (FETs).

Depending upon the isolation technique used, the bipolar ICs are further classified as p-n junction isolation ICs and dielectric isolation ICs.

Depending upon the type of FET used, the unipolar ICs are further classified as MOSFET unipolar ICs and JFET unipolar ICs.

Table 1.2.1 gives the total information about the IC families on the basis of substrate used, structure of IC, active and passive devices used and finally the application of the IC. 

Review Questions

1. Write short note on classification of integrated circuits.

2. Give comparison between the IC families on the basis of structure, substrate used, active and passive devices and applications.

3. What are the new trends in Integrated circuit technologies and explain about its scope for future generation ?