ads1299 pin64 output or agnd

Alexander Basaev

In documentation "SBAS499A– JULY2012– REVISED AUGUST 2012", page 10, pin 64 marked as "Analog output, Leave as open circuit".

In "SLAU443B–May 2012–Revised January 2016", page 50, pin 64 tied to AGND.

I`m a bit confused. It`s seems to me, that it is not good to tie analog output to ground.

Am I wrong? Is it correct to tie output to ground? How dose this impact on system performance and current consumption?

over 7 years ago

0 Brian Pisani over 7 years ago

TI__Mastermind 38745 points

Hey Alexander,

It should be ok to do either. I don't expect to see any negative consequence from tying it to ground, but floating it may save incremental space on the PCB.

Regards,
Brian

0 Alexander Basaev over 7 years ago in reply to Brian Pisani

Prodigy 25 points

Hi, Brian.

But in question:

You told that: "the only thing I found that could be causing overheating is pin 64 being tied directly to ground."

So my question is:

Is pin 64 output? Or it is some sort of input? Or it is power pin? Or it is completly unconnected pin?

0 Brian Pisani over 7 years ago in reply to Alexander Basaev

TI__Mastermind 38745 points

Hey Alexander,

The pin is an analog output whose state should be hi-z. I knew it was an output but I previously had not verified its behavior when I told you to leave it floating. I also doubt it was the source of the problems you were having previously.

Regards,
Brian Pisani

Data converters

Data converters forum

ads1299 pin64 output or agnd