I will be using AD9515 as clock divider for a part that is 10MHz-1GHz synthesizer with LVPECL and LVDS up to 1GHz and LVCMOS up to 250MHz. How can I estimate the power requirement (max.current draw) for the AD9515?
Start with the datasheet power dissipation numbers for both outputs at 125 MHz. (510 mW).
LVPECL has relatively constant power consumption with respect to Fout.
For the CMOS driver, it looks like a key piece of information is missing from the datasheet, which is the additional current draw versus frequency for only the CMOS driver.
Fortunately, the AD9516 has the same driver design and is on the same process. The amount of additional current from 125 to 250 MHz for one CMOS driver is about 10 additonal mA. This is the number to add to the nominal power consumption. You should at about 20% for a max number, so now you're up to 12mA.
Multiply 12mA by3.3V and you have about 42mW of additional power over the 510 mW number.
Note that this is for one single-ended CMOS driver. You should double that if you're using both CMOS drivers.