14-bit D/A converter helps synthesize entire cable spectrum into a single RF port

February 23, 2011 // By Paul Buckley
Analog Devices, Inc. , has introduced a 14-bit D/A converter that enables cable television and broadband operators to synthesize the entire cable spectrum up to 1 GHz into a single RF (radio frequency) port, while consuming a maximum of 1.1 W of power. The AD9739A 14-bit, 2.5-GSPS D/A converter’s wide bandwidth and dynamic range enables cable operators to increase the QAM (quadrature amplitude modulation) channel densities by 20 times over the densities found in today’s cable modems.

Competing D/A converter solutions require an additional 28 LVDS (low-voltage differential signaling) pairs for the data interface and consume nearly three times more power than ADI’s AD9739A D/A converter.

The AD9739A D/A converter features ADI’s proprietary mix-mode function, which supports the high-fidelity digital synthesis of RF signals at up to 3.6 GHz. The combination of best-in-class, 2.5-GSPS bandwidth and 14-bit dynamic range with a direct-to-RF core allows broadband and next-generation wireless equipment designers to use a single-transmit D/A converter architecture that eliminates a low-pass filter and one mixer or modulator stage.

 The AD9739A converter is well suited for a broad range of applications, including wireless-communications equipment, instrumentation and defense electronics. The device provides multi-carrier capability up to the Nyquist frequency in baseband mode and uses ADI’s mix-mode function to generate RF signals in the second and third Nyquist zones.

AD9739A 14-bit, 2.5 GSPS D/A converter features and benefits:

  • Operates from 1.8-V and 3.3-V supplies for maximum power consumption of 1.1 W.
  • Low noise and intermodulation distortion performance enable high quality synthesis of wideband signals up to 1 GHz.
  • Dual-port interface with double-data-rate LVDS data receivers supports the maximum conversion rate of 2.5 GSPS.
  • Proprietary switching technique enhances dynamic performance.
  • Output current is programmable from 8.7 mA to 31.7 mA.

Availability and Pricing

The 2.5 GSPS 14-bit AD9739A packaged in a 160-ball CSBGA is available now and is priced at $43.69 each in 1,000-unit quantities.

More information about the AD9739A D/A converter at

Visit Analog Devices at www.analog.com