Datasheet

DAC7734
24
SBAS138A
www.ti.com
(3)
FIGURE 13. 4-to-20mA Digitally Controlled Current Source (1/2 DAC7734).
I
OUT
V
PROGRAMMED
R
SENSE
250Ω
I
OUT
V
PROGRAMMED
R
SENSE
250Ω
V
OUT
A Sense
V
OUT
A
AGND
V
SS
V
REF
L AB Sense
V
REF
L AB
V
REF
H AB
V
REF
H AB Sense
V
OUT
B Sense
V
OUT
B
48
47
46
45
44
43
42
41
40
39
DAC7734
5V
OPA2350
80kΩ
20kΩ
1.0V
2200pF
100Ω
1000pF
1000pF
2200pF
+V
+V
100Ω
I
VV N V
OUT
=
















+




51
250 65 536
1
250
–
•
,ΩΩ
Figure 13 shows a DAC7734 in a 4mA to 20mA current
output configuration. The output current can be determined
by Equation 3:
At full-scale, the output current is 16mA, plus the 4mA, for
the zero current. At zero scale, the output current is the offset
current of 4mA (1V/250Ω).