Analog Devices, Inc. ( ADI), a global leader in high-performance signal processing technology and the data converter market share leader*, today introduced two RF (radio frequency) D/A converters that are able to synthesize the entire downstream (transmit) cable spectrum from a single RF port. Supporting data rates up to 2.8 GSPS, the single-channel, 14-bit AD9129 and 11-bit AD9119 RF D/A converters allow cable operators to reduce the total system power and component count of CATV (CMTS) infrastructure equipment, simplify system design, and lower total bill of material costs. The new RF D/A converters support from one to as many as 158 CATV carriers and include an optional 2× interpolation filter that reduces output filtering complexity by effectively increasing the D/A converter update rate by a factor of two. In its Mix-Mode™ super-Nyquist operation, the AD9129 can reconstruct spectrally-pure RF carriers in the 2nd and 3rd Nyquist zones, eliminating a mixing stage while still maintaining exceptional dynamic range at up to 4.2 GHz.
“The AD9129 RF D/A converter utilizes ADI’s patented quad-switch architecture to synthesize the full dc-to-1.4 GHz baseband output spectrum, which will greatly simplify and improve downstream DOCSIS 3.0-compliant transmitter design,” said Carlton Lane, marketing manager, High-speed D/A Converter group, Analog Devices. “This D/A converter’s new level of performance and functionality enables cable infrastructure equipment manufacturers to implement the complete downstream signal chain in a smaller footprint, at one-third the power, and using fewer signal chain components. These are all important design considerations in today’s CMTS service environment.” More About the AD9129 14-bit RF D/A Converter The AD9129 RF D/A converter enables industry leading direct RF synthesis performance with minimal loss of output power across its output spectrum. The device also enables dual-edge clocking operation, effectively increasing the converter update rate to 5.6 GSPS when configured for Mix-Mode or 2× interpolation mode. Its high dynamic range and bandwidth enable multicarrier generation up to 4.2 GHz. The device dissipates only 1.1 W at the full 2.8-GSPS D/A converter update rate.