ASIC vs. FPGA: Which To Choose & Why
ASIC and FPGA are both acronyms describing implementation of Integrated Circuit (IC) technology. ASIC is a acronym for an Application Specific Integrated Circuit. Application specific means that the Integrated Circuit is custom designed to exactly fit the needs of an application. Silicon area use is a driving factor in production part cost. Since an ASIC only includes the needed resources required to accomplish the design task, silicon area is optimized, making ASIC implementations the lowest cost solution in medium to high volume applications.
What is ASIC?
ASIC architecture can range from a Gate Array , were predefined building blocks are selectively interconnected during layout process (lower development cost, higher unit price), to a full custom implementation where each transistor is optimized for a required function (higher development cost, lower unit price). Once the ASIC design is complete, the ASIC must then be manufactured in specialized fabrication facilities, which takes up to 12 weeks for engineering prototypes and 20 weeks for fully assembled and tested production ASIC.
What is FPGA?
FPGA is an acronym for Field Programmable Gate Array. Similar to ASIC Gate Array architecture, an FPGA consists of predefined hardware resources. Unlike an ASIC gate array, FPGA hardware resources can be programmed (connected or disconnected from each other) in the field with a simple programming device. Once a digital design is completed, the Field Programmable Gate Array can be immediately programmed and deployed. However, such incredible flexibility is not free, FPGA parts have a very high production unit price as compared to an ASIC unit price. FPGA technology is an excellent prototyping vehicle for digital logic and a perfect solution for low volume products.
Although ASIC implementations require more up front design cost and longer fabrication time than FPGA, ASIC offers a number of important advantages beyond just a lower production unit cost. An ASIC can integrate valuable technology not available in an FPGA, including, analog functionality for signal conditioning and acquisition of sensor input, asynchronous logic for use of smaller footprint and lower system clock speed, power supply management, blocks optimized for specific function such as power supply control, low power functionality, and many other optimizations that add value to a design.
ASIC vs FPGA Comparison
|ASIC – Application Specific Integrated Circuit||FPGA – Field Programmable Gate Array|
|Low unit cost||High unit cost|
|High development cost||Low development cost|
|Long manufacturing cycle||Short manufacturing cycle|
|Low power dissipation||High power dissipation|
|Small footprint and multiple package options||Large footprint and limited package options|
|Analog, Digital, and Mixed-Signal technology options||Digital with limited Analog IP blocks|