I have a AD9257 for analog-digital conversion of my system. I have a clock frequency approiximately 8 MHz for AD9257.
AD9257 fco pin works well at 8 MHz clock too. However, dco pin has some unstability at 8 MHz. Also, when I increase clock frequency to 25 MHz dco pin is always 1.8 V.(VDD)
Is my usage optimum for AD9257 with 8 or 25 MHz clock? Should I use 40 MHz since ADC has 40 MSPS convertion rate? What can be the reason I cannot see dco signal in my system?
Thank you for your attetion.