ADS5407: Is there any way to turn off LVDS outputs at power-up?

Mike,

There is not. One option is to not power up DVDDLVDS, do a register write to disable the outputs, then power up DVDDLVDS. This is the only thing that I can think of that might work.

Regards,

Jim

JIm,

Thank you for getting back to me about this question.  On the board that this part is mounted to, the DVDDLVDS signals are all directly connected to the 1.8 Volt I/O power supply rail.  The ADS5407 is also in a BGA package.  Therefore, I cannot isolate the DVDDLVDS signals to not power them up.  So unfortunately, by the time I were to do a register write to disable the LVDS outputs, this power-up issue we're having would have come and gone.

Regards,

- Mike A.

Mike,

I figured you would not be able to do this but this was the only thing I could think of. By any chance, did you try holding reset low and see if the drive is reduced?

Regards,

Jim

JIm,

If you're talking about holding the SRESET (a.k.a. SRESET B) signal low, no we haven't tried this.  Coincidentally, I had actually suggested to to a coworker that we try this, but he pointed out that the description for this pin in the TI datasheet states that it's the "Serial interface reset input." so we didn't try it .  But we can certainly do an experiment to try holding this signal low during power-up to see if it has any impact on the LVDS outputs at power-up.