ADS1120: High bandwidth filter characteristic

Hi Ryuuichi,

We do not have additional information about the filter response beyond the frequency limits shown in figure 52.

Can I ask why you would need this information? Are you questioning if it is necessary to have an anti-aliasing filter in your system, or if it is possible to just let the ADC's digital filter perform this function? I would recommend having a simple RC filter at the input of the ADC to act as an anti-aliasing filter.

-Bryan

Hello Bryan-san,

Thank you for your reply.

* The background of this question is that we have an antialiasing filter.

However, in this case, we need to confirm high bandwidth characteristic considering following usecases.

* It takes time for the antialiasing filter to become effictive due to problem such as the time constant.
* Noise is injected after antialiasing filter.
=> From viewpoint above, we need to confirm high bandwidth characteristic of internal digital filter(over 200Hz).

Since it is OK not be guranteed data(just test data), could you re-confirm ?

Best Regards,

Hello Bryan-san,

Thank you for your reply.

>I can confirm that this data is not available to provide to you.

Is it due to NDA ? In other words, if we have NDA with TI, can you disclose ?

>I can tell you that the frequency response is a mirror image of the plot shown in Figure 52 when the frequency reaches fMOD, as shown below in a modified image I created.

I have quick question about above.

* Is my undertstanding that most attenuated band is in the 180Hz to 220Hz correct ?

Best Regards,

Hi Ryuuichi-san,

I am looking into seeing if this data can be produced. Right now it does not exist, which is why I cannot provide it to you. I will get back to you in the next 1-2 days.

-Bryan

Bryan-san,

Understood. I accepted your request.

BR,

Bryan-san,

Yes, let me close this thread. When I have question, I will sent you message on privately.

BR,