Datasheet

–10–
REV. C
MAT03
Figure 8. Digitally Programmable Current
Pump—INL Error as Digital Code
The full-scale output of the DAC08, I
OUT
, is a linear function
of I
REF
I
FR
=
256
256
× I
REF
, and I
OUT
+
I
OUT
= I
REF
256
256
The current mirror output is I
OUT
–
I
OUT
= 1, so that if
I
REF
= 2 mA:
I = 2 I
OUT
– 1.992 mA
= 2
Input Code
256






(2 mA) – 1.992 mA.
DIGITAL CURRENT PUMP CODING
Digital Input
B1 . . . B8 Output Current
FULL RANGE 1111 1111 I = 1.992 mA
HALF RANGE 1000 0000 I = 0.008 mA
ZERO SCALE 0000 0000 I = –1.992 mA