Original question:
Hi,
I'm wondering if it's possible to use a single ended AC-coupled input with a pk-pk voltage of about 0.6V to interface to the input of the LMK1D1204? I would be biasing the IN0_N pin to the recommended halfway voltage of 0.3V, but I'm wondering that if the positive input is AC coupled, do I also need to provide a bias to the positive signal?
James,
It would not be possible. The positive signal would need to have a Vth within the common mode range. I would recommend DC coupling as shown in the datasheet.
If you do AC-couple the positive input, you would need to bias the input to match the halfway voltage.
Regards,
Will
Thanks Will. Just to make sure we're on the same page, I'm planning on interfacing my single ended signal such that it looks pseudo-differential in the following way :
Do I need to terminate into 100 Ohms also such that it is similar to LVDS or is this not required? Also, the single ended performance has a recomended frequency up to 250MHz. Just to clarify, should we expect datasheet performance at 250MHz, or is this the point at which performance will start to roll-off?
