PCI Express (PCIe) Clock Applications Overview by IDT

An overview of PCI Express applications and how IDT's industry-leading portfolio of PCIe clock products address the requirements. The video briefly discusses PCIe riser cards, embedded SOC, PCIe storage (NVME) examples.

Presented by Ron Wade, System Architect at IDT. For more information about IDT's PCIe clocks visit http://www.idt.com/go/PCIeClocks.


Hi there, this is Ron Wade. Welcome back to the last part of our series on full-featured PCIe clocks, part five of five, where we will discuss some of the applications for these parts. So, PCI Express applications are everywhere. The traditional places you might think to find them, such as data centers and servers and storage are still there. But PCI Express is growing into areas such as digital cameras, automotive infotainment systems, and consumer entertainment systems, as well.
We have a huge range of parts all the way from the smallest consumer application, to that largest networking and data center application. And the full-featured PCI Express family provides those enterprise levels of performance at the consumer size levels of space, power, and cost.
So one of the key applications for the full-featured PCIe family is PCI Express riser cards, where you are basically taking one clock from a connector and providing multiple clocks to additional connectors. Here I've shown the 9DBL02 device in a motherboard application where the riser card has two slots on it. So there would be a 9DBL02 fanout buffer either on the card itself, most likely, taking the clock from the system board and providing two copies, one to each of the connectors.
So, these parts again, common across all the full-featured devices. The performance levels against the PCI Express specifications give you reduced video error rates and then the zero delay buffers in this application help you manage PCI Express transport delay, although you can also use either this part in the fanout buffer mode or the pure fanout buffers as well. And again the parts are offered in a 100 ohm output impedance for that environment, and 85 ohm output impedance which is often seen in the Intel application space.
Another key application for these is with embedded SoCs and here we're using an NXP QorIQ device that would be running in a single oscillator source clock mode, where the only clock into the SoC is a 100 MHz PCI Express clock, in this case coming from a 9FGL0841. These devices often have PCI Express SerDes on them so I've shown this part driving two SerDes inside the NXP processor. And given that the A41 has eight output pairs, that leaves five additional outputs to drive other devices. I've also shown the pin out over here on the right. It's a 48 pin, 6x6 QFN and the footprint is shown at the bottom illustrating the 6x6 nature of the package.
The other growing application, key application, is PCI Express storage or sometimes called NVME. You've got PCI Express drives that are plugged into some sort of mezzanine or riser card. I've shown an IDT retimer in the brown box here, and you've got a system board which has PCI Express data going into the retimer, going up to the drives. Now the system board may be providing you with a clock, and if it is, then you would use a 9DBL device. A five output part is ideal because you've got one clock then going to the PCIe retimer and the other four clocks going to the four drives that are illustrated here. 
If you're in an SRIS environment, the system board may not be providing you with a clock, in which case you would use a 9FGL device to generate the clocks. In this case, you would use the six output part and have an extra one left over for other users, and it would drive the retimer and the four drives. That's it for the series, actually, of full-featured PCI Express parts. Thank you very much for watching and I hope you enjoyed it and learned something. Thanks.