Hello Vladimir,
With the DAC3482 configured in 1x interpolation mode, the maximum DAC update rate is 625MSPS. This is primarily limited by the input LVDS bus. Some devices may run a little bit faster, but we cannot ensure that all devices would behave the same way. Unfortunately, the input rate cannot be increased by reducing the DAC resolution since the input data are being latched in a parallel fashion.
If you need a straight DAC (without interpolation feature) that accepts input data up up to 1250MSPS, then you may need to consider the DAC5670. If you can lower your input rate to 1GSPS, you may also consider the DAC5681, DAC5681z.
If your design schedule allows you to evaluate our products that are being developed in our roadmap, we can get you in touch with our field sales team for further discussion.
-Kang