Digital integrated circuits are categorized based on the complexity of their circuits. The categorization is based on a number of logic gates that are contained inside a single package. Integrated circuits are categorized as small-scale, medium-scale, large-scale, very large scale, ultra-large, Wafer-scale, SoC and 3D-IC levels.
Contents
Small‐scale integration (SSI)
Such devices comprise numerous independent gates in a single package. Gate number in SSIs is generally less than 10. The inputs and outputs of the gates are connected straight to the pins in the package.
Medium‐scale integration (MSI)
MSIs comprise 10 to 1,00 gates in a single package. MSI applications involve decoders, adders and multiplexers, registers and counters.
Large‐scale integration (LSI)
LSI devices contain thousands of gates in a single package. Devices having 100 to 9999 logic gates are categorized under LSIs. LSI applications involve digital systems such as processors, memory chips, and programmable logic devices.
Very large‐scale integration (VLSI)
VLSIs contain large number of gates within a single package. Devices having 10 000 to 99 999 gates are classified under VLSIs. Practical applications of VLSIs involve large memory arrays and complex microcomputer chips. VLSIs are small sized and economically available devices.
Ultra-large-scale integration (ULSI)
ULSI was proposed for chips having more than 1 million transistors. ULSI have logic gates that are greater than 100 000.
Wafer-scale integration (WSI)
WLSI refers to the method of building very large integrated circuits that uses an entire silicon wafer in order to produce a single “super-chip”.
System-on-a-chip (SoC Integration)
SoC refers to the integrated circuit in which all the components required for a particular system are included on a single chip.
3D-IC
It refers to the integrated circuits in which two or more layers of active electronic components that are integrated both vertically and horizontally into a single circuit.
| Acronym | Integration | Number of Transistors | Number of Logic Gates |
|---|---|---|---|
| SSI | Small-scale integration | 1 to 10 | 1 to 12 |
| MSI | Medium-scale integration | 10 to 500 | 13 to 99 |
| LSI | Large-scale integration | 500 to 20 000 | 100 to 9999 |
| VLSI | Very large scale Integration | 20 000 to 1 000 000 | 10 000 to 99 999 |
| ULSI | Ultra-large-scale integration | 1 000 000 and more | 100 000 and more |