I am using I210-IT in my design.
As Intel recommends, I have used internal regulators for 1.5V and 0.9V.
The problem is that the 1.5V regulator cannot reach 1.5V, there seems to be too much current consumption on that rail.
I followed the reference design scheme, I also tried to increase and decrease the total capacity connected to the 1.5 V rail, but the voltage stuck at 0.9 V, and, this cause the 0,9V stuck at 0.7V 0.8V.
If I connect an external power supply to the 1.5 V rail, everything works as it should.
The external power supply provide to the chip only few mA, but those are enough to keep the 1.5V rail to 1.5 V, and leave the 0.9V rail free to reach 0.9V.
The main power rail is stable at 3.35V, and, i measured the 1.5 and 0.9V directly on pin 39 and 38 of the i210 chip to exclude the voltage drop on the pcb traces.
I also checked all the power rails along the whole pcb and there are not significant voltage drops.
What can i check? Where could the problem be?
Thank you for contacting Intel Embedded Community.
Could you please let us know how many units of the project related to this circumstance have been manufactured? How many are affected? Could you please give the failure rate? Also, could you please list the sources that you have used to design it and if it has been verified by Intel?
We are waiting for your answer to these questions.
Thanks for the reply.
Before making the final board, I made a simple PCI-e test board just to make sure everything was designed properly.
At the moment I only have one test board assembled, but I can make another one, i have got some extra pcbs.
But if I boost up the 1.5V rail with an external power supply, everything works fine, so I suppose the pcb is ok.
I have replicated, as far as possible, the I210-AS / IS REFERENCE SCHEMATIC ID 490116.
I replicated the power schematic as it is on Intel schematic, but i thake the 3.3v directly from PCI-e connector.
Just to be sure, I bought a commercial PCI-e board with I210 and swapped the chips, but nothing has changed.
Both chips on the commercial board works well, both chips on my board has the issue.
So the problem is on my test board.
I compared the commercial board to mine, but I didn't notice any big differences.
Thanks for your update.
We suggest that your schematics and layout implementation should be verified by Intel. For this propose, please follow the procedure stated at:
While preparing the components for mounting a second test board, I noticed that the capacitor between CTOP and CBOT that had been mounted on the first board had an incorrect value.
I replaced it with the right one and everything works well.
Sorry for my mistake. Thanks anyway for the support.