The AD9851 is a highly integrated device that uses advanced

DDS technology, coupled with an internal high speed, high

performance D/A converter, and comparator, to form a dig i tal ly

programmable frequency synthesizer and clock generator funcTIon.

When referenced to an accurate clock source, the AD9851

generates a stable frequency and phase-programmable digiTIzed

analog output sine wave. This sine wave can be used directly as

a frequency source, or internally converted to a square wave for

agile-clock generator applicaTIons. The AD9851’s innovaTIve

high speed DDS core accepts a 32-bit frequency tuning word,

which results in an output tuning res o lu tion of approximately

0.04 Hz with a 180 MHz system clock. The AD9851 con tains

a unique 6? REFCLK Multiplier circuit that eliminates the

need for a high speed reference oscillator. The 6? REFCLK

Multiplier has min i mal impact on SFDR and phase noise charac

ter is tics. The AD9851 provides fi ve bits of programmable

phase mod u la tion resolution to enable phase shifting of its

output in in cre ments of 11.25°.

AD9851,pdf datasheet (CMOS 180

AD9851,pdf datasheet (CMOS 180