There are a number terms that are used frequently to describe the various forms of semiconductor devices used in the industry. An ASIC is one of them. Other terms are rf ic/ wireless ic, an analog ASIC, a MMIC and so on. So what are the differences between these devices? Ultimately all of these devices are semiconductor integrated circuits, indicated by the ic ( or integrated circuit abbreviation). However there are some differences between the various forms of these integrated circuits that lead to the differing nomenclature. Generally if there is no descriptive abbreviation before or after the “ic”, then an ASIC is considered to be a digital device consisting of logic gates, digital memories, microprocessors or microcontrollers and associated circuits all integrated on to a relatively large piece of silicon. An analog ASIC or an analog ic is usually made up of mostly analog circuitry such as amplifiers, comparators, A/D converters, D/A converters,operational amplifiers, analog comparators, voltage references, regulators, etc. A pure analog ASIC or ic operates in the analog domain. It is usually smaller in size than a typical digital ASIC. An rf ic is distinguished by integrated circuitry such as transmitters, receivers, PLLs, modulators, frequency multipliers, rf amplifers, rf power amplifiers, mixers, inductors, transformers, baluns etc. An rf ic also operates at higher frequencies ( typically up to 1 Ghz). A mmic is a monolithic microwave integrated circuit. It may have the same type of circuitry as an rf ic but the frequencies of operation are much higher that rf ics. Currently mmics may be found operating at frequencies in excess of a 100 Ghz. A further type of device referred to as a mixed signal ic has both analog and digital circuitry on it. Sometimes the digital ciruitry is dominant sometines the analog circuitry is dominant.

ASIC stands for “Application Specific Integrated Circuit”. This means that an ASIC is designed to be used in very specific applications. Another term for it is “custom” chip. For ASICs a customer specifies certain requirements and specifications and the ASIC supplier then designs to those specifications and supplies the ASIC to the buyer. As such, ASIC has become a generic term. The usage of ASICs has become popular owing to a number of features that ASICs offer. First, the ASIC is usually very small. So it saves space on a board or enclosure that the customer may be using. In some cases there is no way out for the customer,but to use an ASIC. This may be the case, for instance for hearing aids, watches, cell phones. ( Although, strictly speaking a cell phone uses a lot of standard devices in addition to ASICs).An ASIC can be a great cost reduction tool.Insertion costs, discrete device costs, manufacturing costs and other associated costs csn be saved by using ASICs. An ASIC is a very useful tool when it comes to hiding intellectual property ( IP). Most of the circuitry is inside a very small package and can be made to be almost impossible to reverse engineer. Obviously a well designed ASIC can also increase reliabity significantly. No wires to come loose, nor connectors to fail etc. All in all an ASIC can be very useful indeed. To read more about designing an ASIC for yourself please see the article in this blog.