AD9231: lower external voltage reference

Hi HWCRE ,

Thanks for your interest in AD9231,

The VREF directly affects the analog input swing of the ADC which is in most cases twice the VREF. Given that the VREF = 1.0V, the voltage swing is around 2.0Vpp which is stated in the specification set-up.

For your case, the voltage swing of your input will be 1.8Vpp.

Regards,

Xavier

Thanks for the helpful reply. Do you know if are there other characteristics that degrade due to the variation, compared to the value of 1V, indicated in the D.S.?

In consequence of decreasing the analog input swing, most of AC specification parameters, if not all, will be affected. Thanks!

Thank again for the reply. I would like, if possible, to have some numbers or graphs, rather than general indications, to understand if the degradation is acceptable. Bye

Hi HWCRE ,

You can refer to the comparison between the external VREF of 1.0V (2Vpp) and 0.9V (1.8Vpp) below at 0dBFS. As evident in the figure, the AC parameters like SNRFS and SFDR among others degrades when decreasing the VREF. Hope this really helps.

Thanks and regards,

Xavier