An application-specific integrated circuit (ASIC) is a custom-made integrated circuit designed only for a specific use, and not intended for general purpose. They are used in a number of fields such as automotive, medical, telecommunication and industrial sector. An ASIC chip is used in modems, satellites, Bitcoin miners, voice recorder equipment, etc.
ASIC has changed the way devices are designed and manufactured. Using one integrated system has eliminated the use of any additional circuits. Since it costs high, they are recommended only for high volume products.
There are three types of ASIC:
- Programmable ASIC
- Full Custom Design
- Semi-custom Design
The programmable ASIC is further classified into two types:
- Programmable logic devices (PLD)
- Field programmable gate arrays (FPGA)
PLDs are circuits that built in a way that can be reconfigured. They do not have custom customized logic level converters and mask layers. They are used when there is fast turn around and programmable interconnect is required.
FPGAs are more complex reconfigurable circuits. They also do not have a customized mask layer, but have customized logic converters along with programmable interconnect.
Full Custom Design
They are also referred to as handcrafted designs. The analog circuits, resistors, transistors, digital logic and capacitors are all put into the circuit. The advantage of using full custom design is that they take up very little space and integrates analog components into the circuit. This ensures maximum performance and a high degree of flexibility.
However, they require very advance skills set to develop and are costly to develop. They can also take a lot of time to design and manufacture.
Semi-custom design uses a standard catalogue for designing the circuit. All the logic converters are predesigned; however, the mask layers are customized, which makes it an ASIC. This is a great alternative to full custom design as it can be designed much easily and quickly.
There are two types of semi-custom design ASICs:
- Gate Array
- Standard Cell
In a Gate Array based ASIC, there are predesigned positions for logic gates, transistors and active devices and are produced on wafers.
The designer can choose components from a gate array library to easily design the circuit. However, there this is a compromise on the design as the wafer is never utilized completely.
Standard Cell ASIC uses predesigned logic cells known as standard cells. They include logic gates, multiplexers, de-multiplexers, flip flops etc. Standard cells save money and time, but it is difficult to make and maintain a standard cell library.
ASNT Labs is a provider of ASICs circuits throughout the world. They provide complete custom-made design solutions for companies. Their products also include pre-emphasis amplifiers, digital tunable phases shifters, fanout buffers, active power dividers, and clock dividers.