We have received a batch of AD9164 Rev D dds boards
On some of the boards, they work from dold, but fail to start when warm (The red led for the Power on status just stays on)
We can't find a schematic on-line for Rev D (Only rev C)
We have not had this issue with any Rev C boards
Do you have a blue light start up when connected to the ACE software ? In addition, make sure you are following the power sequencing correctly as it could damage the board. The IOVDD, VDD12A, VDD12_CLK, and DVDD domains must be powered up first. Then, the VNEG_N1P2, VDD_1P2, PLL_CLK_VDD12, DVDD_1P2, and SYNC_VDD_3P3 can be powered up. The VDD25_DAC domain must be powered up last. There is no requirement for a power-down sequence.
Is it possible that there is a design error on the AD9164-FMCC-EBZ board Rev D ?
We have noticed that Rev D now uses the LTC2928 Power Supply Sequencer and Supervisor. We can see an open drain output from the Reg in to the LTC2928, which is pulled up to 5 volts. But the input max voltage on the LTC2928 is VCC + .3 which is 3.6 volts. Yet 5 volts is going in?
Is this why we are getting issues with some of the AD9164-FMCC-EBZ board Rev D boards?
Also, where is the schematic for Rev D? (Only Rev C is listed)
5V can go into the VCC pin, if you are not using the HVcc pin on the LTC2928. I believe there is a fault in your board and my suggestion would be to order a new one and replace it. In addition, the schematic for Rev D will be uploaded to analog.com.PDF
Out of a batch of 4, 1 is working fine. One has failed once. 2 fails always after turn on when warm.
Never had an issue with Rev C boards.
I think there is a design issue with Rev 4 and the LTC2928, as it fails before LTC2928 even starts its sequence (Looking at the CAS signal)
Are there any resister values you recommend that we change?
It sounds more like faults with the boards themselves, the LTC2928 could handle the 5V supplied to the part if HVcc is not used. It would be better for you to replace the failed boards as this problem should not happen.