A Fortune 500 company approached us with a design that included an Ethernet PHY chip that was obsolete and going end of life. They asked MSRK Design to find a newer part that could fit into their existing design with a minimum of changes to the rest of the circuitry. And the resulting design needed to pass the stringent FCC and CE emissions standards.
Understanding the Problem:
Initial investigation showed that it was a very old design that used a 7-wire serial 10Base-T device instead of a more modern MII 10/100Base-T chip.
Identifying the Replacement Part:
It wasn’t an option to upgrade the interface to the current state-of-the-art, so we did some digging and found a couple of options. Our choice was a chip designed for MII that could also be bootstrapped to support the older standard.
The chip came on an evaluation board that we modified and wired into the existing design for testing purposes.
Testing showed that the new device worked as we expected.
Implementing the Replacement Part:
We were then asked to modify the schematic and the pcb layout for the new chip, using the customer’s tools. We worked at the customer’s site for a few days to accomplish this, and then took the design through their manufacturing release process to get some prototypes made.
The Results:
When the new boards arrived, we returned to the customer’s site and confirmed that the new design met their performance expectations. The product was then sent to an FCC Compliance testing company, and even with the first board spin we met FCC and CE compliance requirements! As an added bonus, the new design saved $2 per board.
