Analog Devices' DDS Technology Now Available for Low-Power, Portable Electronics

Unlike phase-locked loop (PLL) devices, which suffer from settling times measured in microseconds and fine-tuning limitations, the AD9913 settles in nanoseconds with granularity well below 10 mHz. Other approaches, including field-programmable gate arrays (FPGAs) with embedded DDS functions, have difficulty matching the AD9913's greater than 80-dB spurious-free dynamic range (SFDR) performance on a 100-MHz output signal while requiring higher operating power and the addition of a discrete digital-to-analog converter (DAC) to synthesize the sine wave. The AD9913 includes an on-chip 10-bit high-speed DAC with no price premium compared to a stand-alone DAC. The fine-tuning granularity and higher SFDR of the AD9913 allow it to more quickly and accurately generate a stable signal in the band of interest. In a remote radio-controlled application, for example, such as an unmanned aircraft, this means the operator is less likely to lose contact with the airplane due to frequency interference that can result in a dropped signal.

Larger systems like wireless base stations and test and measurement equipment have been taking advantage of the higher operating-frequency ranges, faster linear frequency hopping and other performance benefits of DDS technology for the better part of a decade, said Kevin Kattmann, product line director of High-Speed Signal Processing, Analog Devices. With the launch of the AD9913, designers of battery-powered devices can now incorporate the same faster switching speeds, fine frequency resolutions and broader frequency spectrum into their products with no price or power penalty.