RGB 24-bit resolution on 12-bit DAC
Answering ... something, probably not the actual question which is starting to appear in little dribs and drabs in comments.
First ... this is a very slow 2-channel 12 bit DAC, with 14 microseconds settling time. That datasheet link should have been in the question.
You are trying to do something with 24-bit RGB. It's unclear exactly what, but some form of &quot;pulse&quot;.
Now 24-bit RGB is NOT 24 bit resolution and a 24-bit ADC is not necessary or helpful. It is 3 channels of 8-bit RGB values (usually video). So you need 3 DAC channels with at least 8 bit resolution, at whatever speed you need to keep up with the input.
So on the face of it, you could use 2 of these DACs, feeding R and G to both channels of the first, and B in one channel of the other. The fact that it's a 12-bit DAC doesn't hurt (apart from generally being slower than 8-bit ones ... and 24 bit ones are much slower still ... see below) and may be an advantage if you find you need gamma correction as suggested in a comment.
BUT
and it's a big BUT...
if you expect this to keep up with the speeds required for video, forget it. It's far too slow.
If you are trying to generate a very long, low-speed pulse covering at least a whole line of a video scan, or e.g. turn a whole screen the same colour, it might do the job. But you haven't told us what the pulse is ... rise time, length, repetition rate ... so there's no way to answer that.
There is another issue : you want to control a laser with each channel (again, in comments : should be in the question). You need to know how each laser is controlled : if your laser driver expects a PWM input, driving it from a DAC makes no sense. And you haven't told us anything about that. As Chris says, start at the laser end.
Or even better, start with what your real requirements are.