Aiming to widen its presence in the 3G wireless infrastructure space, Texas Instruments has unwrapped its next generation, high-performance digital-to-analog converter (DAC). Implemented in 0.18 micron CMOS process, the 16-bit 500 Msample per second (Msps) dual-channel DAC5687 DAC offers optimized gain, phase and offset control features for direct upconversion architectures using IQ modulators in 3G base stations. Featuring built-in signal processing, the DAC5687 decreases noise, and reduces RF design requirements and cuts overall system costs.

Besides supporting the 3G clock rates, it also supports 491.52 MHz clock. To simplify upgrades, it is pin compatible with the prior generation DAC5686. Other key features include signal-to-noise ratio (SNR) of greater than 75 dBFS and 81 dBc intermodulation distortion (IMD3), allowing multicarrier systems to operate with higher output power. It dissipates 700 mW.

In addition to the DAC5687, TI has also release an accompanying part, the GC1115 crest factor reduction (CFR) processor for improving the efficiency of base station power amplifiers. Also incorporated in 0.18 micron CMOS, the GC1115 limits signal peaks, driving down peak-to-average ratio (PAR) of multi-user, multicarrier 3G signals, thereby enabling cellular base station manufacturers to use less-expensive power amplifiers.

Both the parts are sampling now. While the DAC5687 is expected to go into production by early second quarter, the GC1115 is slated for production in March.

For more information, visit www.ti.com.