[time-nuts] Power Supply for AD9852 / AD9854

d0ct0r time at patoka.org
Sun Mar 16 12:34:08 EDT 2014

I would assume that using two voltage regulators will spread the load. 
For the AD9851 I'am planning to put external radiator glued on top of 



> those parts dissipate a fair amount of heat, and they're not very big.
> If you turn on everything in the 9854 AND run it at 300 MHz clock, it
> draws about 1.2 Amps (@ 3.3V) which is about 4 Watts.. that's a lot of
> power to get out of the part and keep Tj reasonable. Board layout to
> get the heat out is very important.  If they get too hot, they start
> to act flaky.  You get extra spurs and more importantly, they don't
> respond to the programming properly (e.g. you send the serial stream
> to program frequency X, and instead it programs some different
> frequency).
> "The heat sink of the AD9854ASVZ 80-lead TQFP package must
> be soldered to the PCB. "
> "Adequate dissipation of heat from the AD9854 relies on all
> power and ground pins of the device being soldered directly to
> a copper plane on a PCB. In addition, the thermally enhanced
> package of the AD9854ASVZ has an exposed paddle on the
> bottom of the package that must be soldered to a large copper
> plane, which, for convenience, can be the ground plane."


More information about the time-nuts mailing list