GENERAL DESCRIPTION
The AD9834 is a numerically controlled oscillator employing a phase accumulator, a SIN ROM and a 10-bit D/A converter integrated on a single CMOS chip. Clock rates up to 50 MHz are supported with a power supply from 2.3 V to 5.5 V.
Capability for phase modulation and frequency modula tion is provided. Frequency accuracy can be controlled to one part in 0.25 billion. Modulation is effected by loading registers through the serial interface.
The AD9834 offers the user a variety of output waveforms. The SIN ROM can be bypassed so that a linear up/down ramp is output from the DAC. If the SIN ROM is not by-passed, a sinusoidal output is available. Also, if a clock output is required, the MSB of the DAC data can be output, or the on-chip comparator can be used.
The digital section is driven by an on-board regulator which steps down the applied DVDD to +2.5 V when DVDD exceeds +2.5 V. The analog and digital sections are independent and can be run from different power supplies e.g. AVDD can equals 5 V with DVDD equal to 3 V, etc.
The AD9834 has a power-down pin (SLEEP) which allows external control of a power-down mode. Sections of the device which are not being used can be powered down to minimise the current consumption e.g. the DAC can be powered down when a clock output is being generated.

FEATURES
   +2.3 V to +5.5 V Power Supply
   50 MHz Speed
   Low Jitter Clock Output
   Sine Output/Triangular Output
   Serial Loading
   Power-Down Option
   Narrowband SFDR > 72 dB
   20 mW Power Consumption at 3 V
   20-Pin TSSOP

APPLICATIONS
   Test Equipment
   Slow Sweep Generator
   DDS Tuning
   Digital Modulation