Trenz Electronic GmbH Support Forum

Trenz Electronic Products => UltraScale => Topic started by: jas on December 16, 2021, 08:51:58 PM

Title: IO Bank VCC shorted to GND on TE0807
Post by: jas on December 16, 2021, 08:51:58 PM
Hi, we are using Zynq Ultrascale+ SoC (module part number: TE0807-03-4BE21-A) with our own carrier board. The module/board have been working fine for a couple of weeks but now the module has stopped working. I found out that Bank 65 power rail is shorted to GND ( <0.5 Ohm).

One subLVDS channel (from Bank 65) is going to a connector on our board and gets connected to another FPGA on a separate board. I checked the resistance between the pins of this channel and it was around a few kOhms (with connector disconnected) and every other LVDS channel has a resistance of around ~100 kOhm. The power rail of this bank is also shorted GND. I removed the Trenz module from the carrier board and found out that the power rail short was on the module itself. I looked at the schematics and saw that there is only one capacitor connected to this rail on the module. I removed the capacitor and the short was still there.

This mostly implies that the short is on the SoC chip. Have I destroyed the chip? Is there a way to solve this problem?

Thanks!
Title: Re: IO Bank VCC shorted to GND on TE0807
Post by: JH on December 17, 2021, 10:31:04 AM
Hi,
QuoteThis mostly implies that the short is on the SoC chip. Have I destroyed the chip?
I think minimum this IO Bank, maybe more.

Can you share your custom carrier schematic? If yes, please send them to support@trenz-electronic.de and we can check one time if we find something which caused this issue.

Other possible reasons, which you can check:
Do you use heat sink? Eventually the module was overheated?
What's with ESD Protection?

br
John
Title: Re: IO Bank VCC shorted to GND on TE0807
Post by: jas on December 20, 2021, 06:24:17 PM
Hi John, Thanks for your reply. I'll reach out to you by email.