At the datasheet of the AD9915 it is writen that SFDR is less then -57 dBc.
Can it be dBFS?
It is very critical for us to know if the information at the datasheet has a
typing (or any) error or if our measurements have a mistake or if our Ev.Board has a problem.
Can you please urgently let us know your opinion about this subject?
Here are our measurements with AD9915 Eval.Board:
* At the Ev.Board: PLL disabled, Sys-Clk = 2,5 GHz, OSK enabled.
* Output Freq = 550 MHz / Amp (ASF) = FFF. With spectrum analyzer the
carrier signal measured as 550 MHz / -0,715 dBm and the spurious measured as
850 MHz / -59,0 dBm.
* When we change the Amp (ASF) to 7FF. Spectrum analyzer measurements are:
550 MHz / -6,730 dBm and 850 MHz / -68,0 dBm.
* When we change the Amp (ASF) to 3FF. Spectrum analyzer measurements are:
550 MHz / -12,755 dBm and 850 MHz / -67,0 dBm.
* So on.
* There occurred lots of conditions like this which can be followed by the
So, when we decrease the amp. of the carrier, the SFDR feature (being
less than -57dBc) of the AD9915 cannot be achieved / doesnot supporrted by the
Can our Ev.Board has a problem or can our measurements have a mistake?
Waitng for your kind reply ASAP.