If it is DC then it hasn't got a frequency.
What do you mean by "accept"?
What do you want to measure, voltage or frequency or both?
If it is frequency what range of frequencies do you want to measure?
If it is voltage what sort of voltage do you want to measure?
It could be, peak, peak to peak, avrage or RMS.
That is too wide for an Arduino with a 10 bit A/D converter. You need at least a 12 bit A/D and possibly a lot more. Especially if you want any degree of accuracy of measurement at the lower end of the voltage range.