RF d/a converters cut pcb space by 25%

Supporting data rates up to 2.8GS/s, the single channel, 14bit AD9129 and 11bit AD9119 d/a converters have the ability to synthesise the entire downstream cable spectrum from a single d/a converter port. They are also said to allow cable operators to reduce the total system power and component count of CATV infrastructure equipment, simplify system design and lower total bom costs. The new modules support up to 158 CATV carriers and include an optional 2x interpolation filter to reduce output filtering complexity by increasing the d/a converter update rate by a factor of two. "The AD9129 rf d/a converter utilises ADI's patented quad switch architecture to synthesise the full dc to 1.4GHz baseband output spectrum, which will greatly simplify and improve downstream DOCSIS 3.0 compliant transmitter design," said the company's Carlton Lane. "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."