Post Go back to editing

AD9706 Rset Value

Hi,

I am using the AD9706 in an application. Right now I have the device input voltage set to 1.8V.

This would give:

Ioutfs = 2mA

Iref = Ioutfs / 32

Iref = 2mA / 32

Iref = 62.5uA

Vrefio = 1.025V

Datasheet states:

Iref = Vrefio/Rset which equals Vrefio/Iref = Rset

For my values above

Rset = 1.025 / 2m

Rset = 1.64k 

The datasheet states: 

"The control amplifier allows a 5:1 adjustment span of IOUTFS from 1 mA to 5 mA by setting IREF between 31.25 μA and 156.25 μA (RSET between 6.4 kΩ and 32 kΩ)." The calculated value of 1.64k is not even in the scale for what the datasheet states though I am assuming that this is in reference to 3.3V input in which Ioutfs = 5mA. 

So for the device to work properly what would the value of Rset be for 1.8V? I would assume that it should be 1.64k though some preliminary testing has shown otherwise where having a 6.49k value for Rset gave me Ioutfs = 2mA . . . please clarify. 

Regards,

Jordan 

Parents Reply Children
No Data