18.4.1 D/A Conversion Formulas for Unipolar Output Ranges

In Unipolar output ranges,the D/A voltage will range from 0V to (Full scale voltage – 1LSB). Thus the full scale range is the same as the full scale voltage.

12-bit D/A:

D/A code = (Output voltage / Full scale voltage) 4096

Output voltage = (D/A code / 4096) Full scale voltage

1 D/A LSB = Full scale voltage / 4096

16-bit D/A:

D/A code = (Output voltage / Full scale voltage) 65536

Output voltage = (D/A code / 65536) Full scale voltage

1 D/A LSB = Full scale voltage / 65536

Example for 12-bit D/A:

Output range is unipolar 0 – 10V (full scale voltage = full scale range = 10V); Desired output voltage = 2.000V.

D/A code = 2.000V / 10V * 4096 = 819.2 => 819

1 LSB = 10V / 4096 = 2.44mV

The following table illustrates the relationship between D/A code and output voltage for a unipolar output range (VREF = Reference voltage).