Here I have a problem with the REF_CLK input for AD9957. I've got an evaluation board for AD9957. But I cannot use the crystal on the board because I can't get a fractional system clock for AD9957, for example 409.2MHz cannot be produced. So I want to use an external REF_CLK instead of the 25MHz crystal. The requirement is that the REF_CLK be between 300 to 400MHz, and could be fractional. Could you please recommend me some chips?
Thanks very much!