The analog output of the DAC can be connected to a pin by writing a ‘1’ to the
Output Buffer Enable (OUTEN) bit in the Control A (DACn.CTRLA) register. The pin used by
the DAC must have the input disabled from the Port peripheral. There is an output buffer
between the DAC output and the pin, which ensures the analog value does not depend on
the load of the pin. The output buffer can only source current, it has very limited
sinking capability.