GENERAL DESCRIPTION

The AD9780/AD9781/AD9783 include pin-compatible, high dynamic range, dual digital-to-analog converters (DACs) with 12-/14-/16-bit resolutions, and sample rates of up to 500 MSPS. The devices include specific features for direct conversion transmit applications, including gain and offset compensation, and they interface seamlessly with analog quadrature modulators such as the ADL5370.

A proprietary, dynamic output architecture permits synthesis of analog outputs even above Nyquist by shifting energy away from the fundamental and into the image frequency. Full programmability is provided through a serial peripheral interface (SPI) port. Some pin-programmable features are also offered for those applications without a controller.

FEATURES

  High dynamic range, dual DAC parts

  Low noise and intermodulation distortion

  Single carrier W-CDMA ACLR = 80 dBc @ 61.44 MHz IF

  Innovative switching output stage permits usable outputs beyond Nyquist frequency

  LVDS inputs with dual-port or optional interleaved single port operation

  Differential analog current outputs are programmable from 8.6 mA to 31.7 mA full scale

  Auxiliary 10-bit current DACs with source/sink capability for external offset nulling

  Internal 1.2 V precision reference voltage source

  Operates from 1.8 V and 3.3 V supplies

  315 mW power dissipation

  Small footprint, RoHS compliant, 72-lead LFCSP

APPLICATIONS

  Wireless infrastructure

  W-CDMA, CDMA2000, TD-SCDMA, WiMAX

  Wideband communications

  LMDS/MMDS, point-to-point

  RF signal generators, arbitrary waveform generators