How to select the Rset in current-steering DAC

[stpluto]

adv7125 rset

Two questions:
In current-steering DAC, the current is convertered to voltage via the Rset. How to choose the value of it?
In the page2 of the ADV7125 datasheet (**broken link removed**), they choose 560ohm, the full scale current is I=Vref/Rset*K*(FFH)*4 and K=7.9896. What's the mean of the K and how to choose the value of K?

Thanks

 

[stpluto]

Who know that pls help me.

 

[anilsaini]

In current-steering DAC or other DAC Rset is output resistor, which is also work as output impedence. This is decided by knowing, what is the input impedence of interfacing circuit to this circuit.

 

[stpluto]

Rset in a off chip resistor and it is not a input imperdance of the interface circuit.