GENERAL DESCRIPTION
The AD9785/AD9787/AD9788 are 12-bit, 14-bit, and 16-bit, high dynamic range TxDAC® devices, respectively, that provide a sample rate of 800 MSPS, permitting multicarrier generation up to the Nyquist frequency. Features are included for optimizing direct conversion transmit applications, including complex digital modulation, as well as gain, phase, and offset compensation. The DAC outputs are optimized to interface seamlessly with analog quadrature modulators, such as the ADL5375 family from Analog Devices, Inc. A serial peripheral interface (SPI) provides for programming and readback of many internal parameters. Full-scale output current can be programmed over a range of 10 mA to 30 mA. The AD9785/AD9787/AD9788 family is manufactured on a 0.18 μm CMOS process and operates from 1.8 V and 3.3 V supplies. It is enclosed in a 100-lead TQFP package.

FEATURES
   Analog output: adjustable 8.7 mA to 31.7 mA,
      RL = 25 Ω to 50 Ω
   Low power, fine complex NCO allows carrier placement
      anywhere in DAC bandwidth while adding <300 mW power
   Auxiliary DACs allow I and Q gain matching and offset control
   Includes programmable I and Q phase compensation
   Internal digital upconversion capability
   Multiple chip synchronization interface
   High performance, low noise PLL clock multiplier
   Digital inverse sinc filter
   100-lead, exposed pad TQFP package

APPLICATIONS
   Wireless infrastructure
      W-CDMA, CDMA2000, TD-SCDMA, WiMAX, GSM
   Digital high or low IF synthesis
   Transmit diversity
   Wideband communications
      LMDS/MMDS, point-to-point