Microwave Journal

Analog Devices’ DOCSIS 3.0-compliant RF D/A converter reduces PCB space by 25%

October 17, 2012

Analog Devices Inc. (ADI), a global leader in high-performance signal processing technology and the data converter market share leader*, 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.

The AD9129 includes a dual-port, source-synchronous LVDS (low-voltage differential signaling) interface that simplifies the data interface to a host FPGA or ASIC. On chip DLLs (delay-locked loops) optimize 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.

AD9129/19 Single-channel D/A Converters Features and Benefits:

  • D/A converter update rate of up to 5.6 GSPS
  • Direct RF synthesis @ 2.8 GSPS data rate
    • DC-to-1.4 GHz in baseband mode
    • DC-to-1.0 GHz in 2× interpolation mode
    • 1.4-to-4.2 GHz in Mix-Mode
  • 1 to 158 DOCSIS 3.0 carriers: 8 QAM carrier ACLR = > 69 dBc
  • By-passable 2× interpolation filters
  • Single/multicarrier IF or RF synthesis
  • Low power: 1.1 W @ 2.8 GSPS (1.3 W @ 5.6 GSPS)

Pricing, Availability and Complementary Products

Product

 

 

Sample
Availability

 

 

Production
Release

 

 

Resolution

(Bits)

 

 

Sample
Rate

(GSPS)

 

 

Price
Each In
1,000
Quantities

 

 

Packaging

AD9129

 

 

Now

 

 

November
30

 

 

14

 

 

2.8

 

 

$59.00

(Pb-free)

 

 

160-Ball
CSP-BGA

AD9129

 

 

Now

 

 

November
30

 

 

14

 

 

2.8

 

 

$69.00

(PbSn)

 

 

160-Ball
CSP-BGA

AD9119

 

 

Now

 

 

November
30

 

 

11

 

 

2.8

 

 

$49.00

(Pb-free)

 

 

160-Ball
CSP-BGA

Other Analog Devices parts that are complementary to the AD9129 RF D/A converter are the ADF4351 wideband PLL (phase-locked loop) for use as the D/A converter clock, and the ADCLK925 low-jitter clock buffer.