• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 46 subscribers
  • Views 274 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

ADS1263: Is it possible to enhance PGA output filtering by increasing CAPx capacitor 10 times ?

Damien Buisson
Prodigy 70 points
Part Number: ADS1263

Tool/software:

Hello all,

The output of the PGA of the ADS1263 is filtered by a 60 kHz differential output first order analog filter, with a 4,7 nF capacitor placed at pins CAPP and CAPN.

At the modulator sampling frequency, Fs = 921 kHz, where we have aliasing problem to DC, the attenuation due to this filter is only -23 dB, which is very low, or i am wrong ?

Is it possible to increase the capacitor value between CAPP and CAPN up to 47 nF instead of 4,7 nF ?

It would give 20 dB more attenuation at Fs, where it aliases at DC.

Thanks !

  • 0
    TI__Guru 52496 points

    Hi Damien Buisson,

    Please use the recommended capacitance value for CAPx. Adding too much capacitance to the output of an amplifier can cause it to become unstable. Our recommendation takes this account, as well as other factors e.g. the required amount of anti-aliasing while also balancing the settling time of the amplifier, etc.

    -Bryan