The AD9737A/AD9739A are 11-bit and 14-bit， 2.5 GSPS high performance RF DACs that are capable of synthesizing wideband signals from dc up to 3 GHz. The AD9737A/AD9739A are pin and functionally compatible with the AD9739 with the exception that the AD9737A/AD9739A do not support synchronization or RZ mode， and are specified to operate between 1.6 GSPS and 2.5 GSPS. By elimination of the synchronization circuitry， some nonideal artifacts such as images and discrete clock spurs remain stationary on the AD9737A/AD9739A between power-up cycles， thus allowing for possible system calibration. AC linearity and noise performance remain the same between the AD9739 and the AD9737A/AD9739A. The inclusion of on-chip controllers simplifies system integration. A dual-port， source synchronous， LVDS interface simplifies the digital interface with existing FGPA/ASIC technology. On-chip controllers are used to manage external and internal clock domain variations over temperature to ensure reliable data transfer from the host to the DAC core. A serial peripheral interface （SPI） is used for device configuration as well as readback of status registers.