Wolfson Microelectronics

12

WM5621L

5

For a DAC, linearity is measured between ZERO input code

( all inputs 0 ) and full scale code ( all inputs 1 ) after offset

and full scale are adjusted out or accounted for in some

way. However, single supply operation does not allow for

adjustment when the offset is negative due to the break-

point in the transfer function. So the linearity in the unipolar

mode is measured between full scale code and the lowest

code which produces a positive output voltage. The code

is calculated from the maximum specification for the

negative offset.

Figure 5: Effect of negative offset (single supply)