"Having the same development tools was critical," Klosterboer continued. "Since Emerson was doing the design and analog portion of the layout, file transfers and exchange of design information was critical. In the past, trying to translate design information from one tools format to another has always been difficult, and can cause delays in the schedule."
Krouth said the project represented "the fastest turn ever" from definition to an approved quality part. "With support from AMIS on design and layout, we were able to hand off a design that they could put into production almost immediately. There was a very short timeæfourteen and-a-half weeksæbetween hand-off and tape-out."
AMIS’ Cameron said time was saved on the project because Emerson had existing parts to give to AMIS’ test engineers. "Typically, test development needs silicon, but in this case we were able to use the existing parts to develop the test in parallel with design and fabrication."
Emerson also provided a product test board to aid testing and verification. "If a customer isn’t willing to give us insight into the end application, it’s difficult to correlate our results with theirs," Cameron noted. "If we don’t have an identical application board for evaluating the part, we see one thing and the customer sees another."
Cameron said Emerson laid out the analog core and designed the digital portion in VHDL, and then transmitted the design files to AMIS for digital layout and final integration. AMIS designed a custom peripheral pad ring for Emerson’s analog core and routed the top level of the circuit, placing the analog core inside the pad ring, routing the digital core, wrapping the cores with the pad ring, and performing top-level verification. The pad ring was designed to incorporate AMIS’ ESD structures, with special attention paid to critical sensor inputs and isolation barriers.
In the end, AMIS fabricated the part on a 0.5_-process significantly tighter than that used by the previous manufacturer Cameron said the replacement ASIC sped through AMIS’ manufacturing facility in 15 days, from ordering masks to prototype delivery and acceptance. That cycle typically takes six to eight weeks. The project was given top priority at each step, with other lots temporarily set aside.
"We cut the fab time by as much as 60%," Cameron said. Chips were then routed to AMIS’ quick-turn assembly facility, diced, and assembled into ceramic packages. "We took them to the test floor, brought the test up, tested 50 prototypes and hand-carried them to Emerson. Within about half an hour, we got the thumbs-up."