Space-saving DOCSIS 3.0-compliant RF D/A converter operates at one-third the power of competing devices

October 16, 2012 // By Paul Buckley
Analog Devices, Inc. has introduced two RF (radio frequency) D/A converters that are able to synthesise the entire downstream (transmit) cable spectrum from a single D/A converter 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 2x 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  dynamic range at up to 4.2 GHz.

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 2x interpolation mode. Its high dynamic range and bandwidth enable multi-carrier generation up to 4.2 GHz. The device dissipates 1.1 W at the full 2.8-GSPS D/A converter update rate.

The AD9129 includes a dual-port, source-synchronous LVDS (low-voltage differential signalling) interface that simplifies the data interface to a host FPGA or ASIC. On chip DLLs (delay-locked loops) optimise timing between different clock domains, while an SPI (serial peripheral interface) is used to configure the AD9129 and monitor the status of read-back registers.

Availability and Pricing

Samples of the AD9129 RF D/A converter are available now with production release schedule for November 30, 2102.  The device is packaged in a 160-Ball CSP-BGA and priced from $59.00 each In 1,000 quantities.

Samples of the AD9119 RF D/A converter are available now with production release schedule for November 30, 2102.  The device is packaged in a 160-Ball CSP-BGA and priced from $49.00 each In 1,000 quantities.

More information about the AD9129 RF D/A converters