Analog Devices introduces superfast direct digital synthesizers

A family of direct-digital synthesizers delivers clock speeds three times as previous devices to support wireless applications requiring fast hopping and/or sweeping. Coupled with an on-chip, high-speed, 12-bit D/A converter, the AD9914 from Analog Devices Inc. (ADI) achieves a speed of 3.5 GSPS, while the AD9915 runs to 2.5 GSPS. Both device cores support advanced digital programmable technology capable of synthesizing frequency-agile, analog output sinusoidal waveforms at up to 1.4 GHz, such as those used in applications like wireless base stations, defense and commercial radar, and secure communications systems.

The DDS devices feature a 32-bit parallel port enabling extremely quick changes to frequency, phase, and the amplitude of the output signal, as well as the programmable modulus function that significantly extends the use of DDS ICs into applications that require exact rational relationships such as signal generators and other lab equipment.

“Increasing clock speeds to 3.5 GSPS on high-resolution DDS ICs allows our customers to generate higher output frequencies with improved dynamic performance,” said Peter Real, vice president, linear and RF, Analog Devices. “ADI’s new DDS products represent a significant step forward, providing better spurious free dynamic range across a much broader frequency band when compared to previous generations. By improving SFDR and enabling fast frequency hopping and fine tuning resolution, AD9914 and AD9915 enable designers to change frequencies in one clock period with ultra-precise tuning of that frequency.”

The AD9914 and AD9915 settle in nanoseconds with granularity well below 200 pHz. Other approaches, including FPGAs with embedded DDS functions, have difficulty matching the SFDR (better than -50dBc) of ADI’s DDS ICs on output signals over 1 GHz and require higher operating power and the addition of a discrete D/A converter to synthesize the sine wave.

Key features include:

• 12-bit D/A converter resolution and 3.5 GSPS (AD9914) and 2.5 GSPS (AD9915) clock rate
• Programmable modulus mode for precise frequency generation and 64-bit resolution.
• Exceptional SFDR performance over a 1.5 GHz tuning range
• Dual accumulators for linear sweeping of frequency, phase or amplitude
• 32-bit parallel port permits pin-access to tuning words for fast and fine shift keying and hopping
• Consumes approximately 2.5 W at full operating speed

The AD9914 and AD9915 DDS ICs are well suited to drive RF output signals from ADI’s broad portfolio of modulators; high speed clocks including the AD9523-1; PLLs and RF amplifiers.

Pricing, availability and complementary products
Product    Sample   Full production    Price each          Packaging
                                                          (100 quantities)

AD9914    Now     Summer 2012      $149.00                  88-Lead LFCSP
AD9915    Now     Summer 2012      $119.00                   88-Lead LFCSP

Download the AD9914 and AD9915 datasheets or review ADI’s portfolio of ADI’s DDS ICs and RF ICs. Get support for DDS design on EngineerZone™, ADI’s online technical support community: http://ez.analog.com/community/dds