The reference voltage can be positive or negative, and the output voltage/current can be positive or negative, that is, four quadrants. DAC itself is a multiplier, also called four-quadrant multiplier DAC! & ltA> If the reference voltage is positive and the output is positive, the DAC is 1 quadrant; & lt2> Further, if the output can output positive and negative signals, the DAC is {1, 4} quadrant; & lt3> If the reference voltage is negative and the output is positive, the DAC is the second quadrant; & lt4> In addition, if the output can be positive or negative, the DAC is a {2,3} quadrant; & lt5> If the reference voltage can be positive and negative, and the output can also get positive and negative signals, then the DAC is four-quadrant.

For example, the reference voltage is a sine signal with positive and negative phases; If the data input of DAC is positive or negative (represented by two's complement), the generated signal is a product relationship. Many dacs have this characteristic. This kind of DAC is generally based on R-2R ladder resistor and CMOS switch, and is powered by positive and negative voltages (but not absolutely). AnalogDevice, Maxim, NS and LT all have these devices.