GENERAL DESCRIPTION

The AD9850 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 complete, digitally programmable frequency synthesizer and clock generator function. When referenced to an accurate clock source, the AD9850 generates a spectrally pure, frequency/phase programmable, analog output sine wave. This sine wave can be used directly as a frequency source, or it can be converted to a square wave for agile-clock generator applications. The AD9850’s innovative high speed DDS core provides a 32-bit frequency tuning word, which results in an output tuning resolution of 0.0291 Hz for a 125 MHz reference clock input.

FEATURES

125 MHz Clock Rate

On-Chip High Performance DAC and High Speed

Comparator

DAC SFDR > 50 dB @ 40 MHz AOUT

32-Bit Frequency Tuning Word

Simplified Control Interface: Parallel Byte or Serial

Loading Format

Phase Modulation Capability

3.3 V or 5 V Single-Supply Operation

Low Power: 380 mW @ 125 MHz (5 V)

Low Power: 155 mW @ 110 MHz (3.3 V)

Power-Down Function

Ultrasmall 28-Lead SSOP Packaging

APPLICATIONS

Frequency/Phase—Agile Sine Wave Synthesis

Clock Recovery and Locking Circuitry for Digital

Communications

Digitally Controlled ADC Encode Generator

Agile Local Oscillator Applications