DAC support

Hi. I'm trying to use the DAC from my due to make a square wave. After analogWrite(DAC0,value), the output voltage won't reach 0V again. I know that the voltage output will always be between 0.55 and 2.75V, but i really need 0V... There is a way to turn off the DAC0? I've tried digitalWrite(DAC0,LOW) with and without pinmode() function.

Best regards,
Jorge