The AD9785 is 12-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 ADL537x 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 AD978x family is manufactured on a 0.18 ?m CMOS process and operates from 1.8 V and 3.3 V supplies. It is enclosed in a 100-lead TQFP package.
- Analog output: adjustable 8.7 mA to 31.7 mA, RL = 25 to 50ohm
- 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 paddle TQFP package
- Applications
- Wireless infrastructure
- WCDMA, CDMA2000, TD-SCDMA, WiMAX, GSM
- Digital high or low IF synthesis
- Transmit diversity
- Wideband communications
- LMDS/MMDS, point-to-point
