SeaMicro found voltage drop problems with their PCB layout. Employing HyperLynx PI quickly located the problem and saved weeks of troubleshooting.
“Sure enough, the places where we measured the 50 mV drop, HyperLynx said it was 47 mV, which is well within the tolerance of our measurements. And the simulation was just dead-on accurate for what we measured across the board and the effects that we saw.”
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product overview: Mentor Graphics' HyperLynx® PI enables quick detection and improvement of PCB Power integrity design and analysis issues.
IOne trait shared by most engineers is a healthy dose of skepticism. This is particularly true with complex tools, such as HyperLynx PI, that perform a tremendous number of calculations very quickly. The engineers at SeaMicro in Santa Clara, California, a startup building highly-power-efficient web page servers, are no different.
The SeaMicro system is that it is physically compact. Each of the blades (PCBs)in the system is roughly 8 ½ x 5 ½ inches, yet contains eight independent processors. With the functionality highly integrated into the ASIC, there is room for all eight. After designing the boards using their in-place rules-of-thumb for power distribution network (PDN) layout, they build a number of boards and began to test them. The quickly began discovering intermittent problems. Because the eight processors onboard share a single power supply, they compete for power, and had different dynamic loads.
Almost serendipitously, Chief Engineer Michael Yolkelson had just attended a HyperLynx PI seminar, less than a month before discovering the intermittent problems. “At the time of the seminar,” he said, “we thought yeah, that’s interesting, but we don’t have a need for it right now’.” Quickly, that had changed. Now, HyperLynx was the only way to analyze the “swiss cheese” power plane, with its many vias. Once they decided that HyperLynx PI could give them the information needed to solve the problem, it didn’t take long to import the schematic to the HyperLynx tool. They began simulation and plotted the voltage drop across the board.
HyperLynx saved SeaMicro 6-8 weeks in re-spins and chasing issues that weren’t contributing to the problem. After using HyperLynx to identify and help fix the problem, they immediately went into production of 200 boards.
“We could have easily spent 6-8 weeks revising the PCB and chasing other things. HyperLynx analytically confirmed what we suspected.”