Analog Devices' DDS IC targets wireless handheld equipment
-- Test & Measurement World, 1/7/2008 7:43:00 AM
In a move to expand the applicability of its direct digital synthesis (DDS) technology into battery-powered industrial, communications, and defense electronics applications, Analog Devices introduces the AD9913 direct digital synthesizer IC specifically designed for wireless handheld equipment. According to the manufacturer, the AD9913 is the first DDS device to deliver a 250-MHz clock rate while consuming as little as 50 mW of power.
Unlike 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 FPGAs with embedded DDS functions, have difficulty matching the AD9913’s greater than 80-dB spurious-free dynamic range (SFDR) on a 100-MHz output signal without 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 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.
Housed in a 32-lead LFCSP (lead-frame chip-scale package), the AD9913 costs $4.65 in lots of 100,000 units.
Analog Devices, www.analog.com.
