Hello, I'm building an electronic load and I'm using the 12 bit DAC6551 and a 4.096 voltage reference, to set the voltage refrence for an op amp which basically controls a mosfet gate voltage (via a 100
![Ohms \$\Omega\$](https://www.eevblog.com/forum/Smileys/default/omega.gif)
resistor) according to the voltage drop across the ballast resistor. The DAC seems to have an integrated op amp on it's output so I was wondering if I need another buffer op amp as I've seen many people use it. I really need a rail to rail output so I think I should use a split supply for the external op amp if I use one. I'm also considering using a 128 bit 5k digital potentiometer to calibrate out any errors and possibly have a x2 gain functionality as well.
I would really appreciate any feedback as if it is possible to just use the internal op amp of the DAC to get the desired functionality as it saves me quiet a bit on buying an external op amp.