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. The AD9850’s circuit architecture allows the generation of output frequencies of up to one-half the reference clock frequency (or 62.5 MHz), and the output frequency can be digitally changed (asynchronously) at a rate of up to 23 million new frequencies per second. The device also provides five bits of digital control input for frequency, phase, and control data.
The AD9850 is a highly integrated direct‑digital‑synthesis (DDS) device that combines a 10‑bit high‑speed DAC and a comparator to generate a spectrally pure sine‑wave output. It can be programmed via parallel byte or serial loading to set frequency, phase and power‑down functions, and operates from a single 3.3 V or 5 V supply.
The device supports a 125 MHz reference clock, provides a 32‑bit frequency tuning word with 0.0291 Hz resolution, and offers five‑bit phase modulation. It is supplied in an ultra‑small 28‑lead SSOP package and is rated for industrial temperature ranges (‑40 °C to +85 °C).
| Reference Clock Rate | 125 MHz |
|---|---|
| Supply Voltage | 3.3 V or 5 V |
| Power Dissipation (110 MHz, 3.3 V) | 155 mW |
| Spurious‑Free Dynamic Range | > 50 dB @ 40 MHz |
| Operating Temperature Range | ‑40 °C to +85 °C |
| Package | 28‑lead SSOP |
| Frequency Tuning Resolution (125 MHz ref.) | 0.0291 Hz |
The device can generate output frequencies up to one‑half the reference clock frequency, e.g., 62.5 MHz when using a 125 MHz reference.
With a 125 MHz reference clock the tuning resolution is 0.0291 Hz.
It operates from a single 3.3 V or 5 V supply.