
AD581
10 V reference guarantees a maximum full-scale temperature
–15V
+5V
coefficient of 8 ppm/°C over the commercial range. The 10 V
reference also supplies the normal 1 mA bipolar offset current
through the 9.95 kΩ bipolar offset resistor. Consequently, the
bipolar offset TC depends only on TC matching of the bipolar
AD581
GND
+V S
V OUT
0.1μF
R3
1.2k ? GAIN TRIM 1
5% R2 2k ?
–10V REF
R1 1k ? 10% 1
SIGNAL
INPUT
1
2
3
4
AD7574
(TOP VIEW)
18
DIGITAL
SUPPLY
RETURN
offset resistor to the input reference resistor and is guaranteed
to 3 ppm/°C.
0V TO +10V
ANALOG
SUPPLY
RETURN
5
GROUND
INTERTIE
ANALOG
GROUND
1 R1
AND R2 CAN BE OMITTED IF GAIN TRIM
IS NOT REQUIRED.
Figure 15. AD581 as ?10 V Reference for CMOS ADC
–15V +5V/+15V
24
23
22
21
20
19
18
17
16
15
14
13
+15V
0.1μF
0.1μF
6
1
2
5k ?
(8k ? )
11
10
CONTROL AMP
SUMMING 4
0.5mA
PNP LOGIC SWITCHES AND LEVEL SHIFTERS
5k ?
(8k ? )
9
2
+V S
JUNCTION
OP1177
AD581
V OUT
10V
GAIN ADJ.
5
100 ? , 15T
R2
19.95k ?
CONTROL
AMP
A
12
3
OP AMP
OUTPUT
GND
AD565A
8
R3
3.0M ?
+15V
R4
20k ? , 15T
3
9.950k ?
(15.95k)
–15V
A
–15V
7
UNIPOLAR
OFFSET ADJ.
R1
100 ? , 15T
BIPOLAR OFFSET ADJ.
Figure 16. Precision 12-Bit DAC
Rev. C | Page 10 of 12
A = ANALOG GROUND