Component Density

The number of elements per chip in an IC is called the component density. There has been a steady increase in the number of components that can be fabricated on a single chip. There is an absolute limit on component density, imposed by the atomic structure of the semiconductor material literally, the size of the atoms! Technology has begun to approach that barrier.

Small Scale

In small scale integration (SSI), there are fewer than 10 transistors on a chip. These types of ICs can carry the largest currents, and can be useful in voltage regulation and other moderate-power applications.

Medium Scale

In medium scale integration (MSI), there are 10 to 100 transistors per chip. This allows for considerable miniaturization, but it is not a high level of component density, relatively speaking. An advantage of MSI (in a few applications) is that fairly large currents can be carried by the individual gates. Both bipolar and MOS technologies can be adapted to MSI.

Large Scale

In large scale integration (LSI), there are 100 to 1000 transistors per semiconductor chip. This is an order of magnitude (a factor of 10 times) more dense than MSI. Electronic wristwatches, single-chip calculators, and simple microcomputers are examples of devices using LSI ICs.

Very-Large-Scale Devices

Very-large-scale integration (VLSI) devices have from 1000 to 1,000,000 transistors per chip. This can be up to three orders of magnitude more dense than LSI. Microcomputers and memory ICs are made using VLSI.

Ultra-Large-Scale Devices

You might sometimes hear of ultra-large-scale integration (ULSI). Devices of this kind have more than 1,000,000 transistors per chip. The principal uses for this technology are in the fields of highlevel computing, supercomputing, robotics, and artificial intelligence (AI).