More Base Station DAC Performance with Less Power and Size

As cell phones improve, offering more features and higher data transmission rates, base station manufacturers must provide more with less.  More bandwidth, more channels, more quality of service with less power, less space and less cost.  On March 21, 2011 Texas Instruments Incorporated announced the availability of three new 16-bit DACs that will help base station manufacturers accomplish exactly that.

Part number DAC3484 is a quad DAC with an interleaved 16-bit input bus.  It has a sample rate of 1.25 GSPS and 2X -16X interpolation, which allows a 312.5MSPS input each of its on four paths.   Part number DAC3482 is a dual DAC, also with 2X - 16X interpolation, which allows an input rate of 625MSPS on each of its two channels.  Finally, part number DAC34H84 is a quad DAC with a wider 32-bit input bus, which allows a sampling rate of 625MSPS on each of its four paths.

Let’s focus on the DAC3484.  Its sampling rate is 25% faster than its nearest competitor.  It needs only 250mw of power, 65% less than its competition.  It fits in a 9mm X 9mm multi-row QFN package, 40% smaller than its nearest competitor.  It has an internal low-jitter 2x to 32x phase locked loop timer, which eliminates the need for an external, low-jitter clock multiplier to match the interpolated rate.  This is doing more with less.

The DAC3484 has other advantages.  One is that using offset, gain, group delay and phase control for system calibration can significantly improve sideband suppression, essentially eliminating sidebands.  Another is that the faster sampling rate enables a designer to make the DPD (Digital Pre-Distortion) feedback loop incorporated into many base station designs more effective with less design effort.  There are others.

These DACs check off nearly every block on a cell phone base station designer’s dream check list.  Seldom does a designer get so much more performance along with reduced power and a smaller package.  These are great DACs in small packages.

Morry Marshall
VP Strategic Technologies