ADS131A04: XTAL frequency range

Mark,

Using an external crystal of 14.7456MHz should work. If you look at the recommended operating conditions, the low end of the operating frequency is 0.4MHz (as an external clock). The crystal frequency you want to use isn't substantively different than the original 16.384MHz. It's only 10% lower than the nominal value.

While I don't know of any specific tests run to check lower crystals, I don't think it would be a problem to run it with a 14.7456MHz crystal.

Joseph Wu

Hello Joseph,

you are Right for a external clock frequency.

The Minimum is 0.4 MHz.

But I mean the XTAL Clock frequency (2 rows lower)!

Here, the max. is 16.5 MHz and the min. is not specified!

Regards

Mark

Mark,

I understand that I pointed out the specification for the external clock frequency. I do think that the crystal will work, but I don't believe that we've tested it for any other crystal frequencies other than 16.384MHz. In the datasheet, the crystal section only lists recommendations for the given frequency.

My point in the last post was that the operating specifications generally do not get worse as the operating frequency gets slower. Typically, the specification will get worse when the operating frequency gets faster, giving less time for sampling to settle in the ADC. Going back to the last post, I don't think that 14.7456MHz is a substantial difference from the 16.384MHz nominal clock. Again, this is only a drop of 10% in the clock frequency. If this is a strong concern for your system, I would recommend using a standalone oscillator.

Joseph Wu