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°.