i.MX RT1170 ADC input design

[TCL_1]

Hi,

I'm designing a MIMXRT1175DVMAA based Board,  and I want to know if it is ok to have no voltage follower buffer in front of the ADC input.

As show in figure below, the acceptable maximum Ras(external analog source resistance) is 5 KOhm, does this mean the SOC internal input impedance (pointed below) is 5M Ohm around? Therefore, if a <5K Ohm analog source without buffer ok for low accuracy required ADC design?

thanks in advance!

Tyrone