The AD9162 is a 6 GSPS, 16-bit RF DAC. With a special interpolating mode, called "FIR85 enabled", you can effectively run the DAC at 12 GSPS with the same 6 GHz input clock. So, if you ran the DAC at 4 GHz input clock and enabled the interpolating mode "FIR85 enabled", you would achieve an 8 GSPS DAC. You could use the AD9161 and achieve 11-bit resolution instead of the 16-bit resolution of the AD9162.
