Digital and mixed-signal ASIC redesign - the answer to discontinued parts

Specialist in the development and custom production of embedded systems and optoelectronics, MAZeT has devised a redesign strategy for digital and mixed-signal ASICs (application-specific integrated circuits) as an answer to discontinued parts. With this move, MAZeT is 'guaranteeing' the future operability of existing electronics developments, says the company. Commenting, Dr. Fred Grunert, managing director, MAZeT, said: “ASICs offer significant benefits compared to standard ICs. An electronics concept geared towards a specific application contains precisely the required function range, which consequently reduces costs and results in a compact solution. The electrical properties are also improved. On the downside, parts are only available for approx. six to eight years, and stock-keeping is limited to no more than two years. To help companies struggling with these issues, MAZeT developed the redesign solution. A redesign increases availability and also makes it possible to further optimize the ASIC.” MAZeT is designing the new ASIC to be compatible to the original ASIC both in terms of its functionality and connection options, keeping follow-up to a minimum. The semiconductor technology is selected based on the premise that it is available over the long haul. MAZeT thus demonstrates that an ASIC redesign can be a highly-efficient alternative. Digital and Mixed-Signal ASICs - There are purely digital and mixed-signal ASICs. As concerns the redesign of digital ASICs, various methods are available, such as, for instance, mask-programmable and standard-cell technology or replacement with a programmable logic module. A mixed-signal ASIC contains digital modules as well as an analog part of variable size. The redesign effort is reduced by using analog or digital IPs, a database that is as complete as possible, comprehensive and detailed documentation of the ASIC, as well as a testing environment. When implementing a concrete redesign order for a mixed-signal ASIC, MAZeT eliminated the weaknesses of the original ASIC: For example, the previous 0.6 µm CMOS technology was replaced by 0.35 µm CMOS technology, which will be available over the long term. The entire pin assignment was retained despite the improved redesign, allowing the existing printed circuit boards (PCB) to be still used. Prerequisites for ASIC Redesign - Successful ASIC redesign is subject to several conditions. The more of these are met, the lower the design risk, development time, and redesign costs. The top priority is to provide a technical description including a requirements specification, circuit plan, high-level language description, netlist, and data sheet in order to ensure functional compatibility. The testing vectors and environment are essential for delivering the proof of functionality needed for series production. What is also important is the description of the dynamic behavior as the logic elements such as gates, flip-flops, memory etc. of a new semiconductor technology often exhibit different delay times and the analog transistors display a different electrical behavior, i.e., they represent different models. Other prerequisites include the testing program for the circuit tester, precise documentation of the ASIC’s electrical functions, the electrical characterization of the input / output behaviour, the supply voltage concept, the ESD and EMC concept, as well as the GDS2 data set, says the company.