MOST OF TODAY’S VLSI DESIGNS ARE CLASSIFIED INTO THREE CATEGORIES

1. Analog:
Small transistor count precision circuits such as Amplifiers, Data converters, filters, Phase Locked Loops, Sensors etc.

2. ASICS or Application Specific Integrated Circuits:
Progress in the fabrication of IC's has enabled us to create fast and powerful circuits in smaller and smaller devices. This also means that we can pack a lot more of functionality into the same area. The biggest application of this ability is found in the design of ASIC's. These are IC's that are created for specific purposes - each device is created to do a particular job, and do it well. The most common application area for this is DSP - signal filters, image compression, etc. To go to extremes, consider the fact that the digital wristwatch normally consists of a single IC doing all the time-keeping jobs as well as extra features like games, calendar, etc.

3. SoC or Systems on a chip:
These are highly complex mixed signal circuits (digital and analog all on the same chip). A network processor chip or a wireless radio chip is an example of an SoC.