Datasheet

AD581
Rev. C | Page 10 of 12
10 V reference guarantees a maximum full-scale temperature
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
offset resistor to the input reference resistor and is guaranteed
to 3 ppm/°C.
1 18
2
3
4
5
AD7574
(TOP VIEW)
AD581
DIGITAL
SUPPLY
RETURN
GROUND
INTERTIE
ANALOG
GROUND
ANALOG
SUPPLY
RETURN
R3
1.2kΩ
5%
GND
+V
S
V
OUT
0.1µF
+5
V
–
15
V
–10V REF
R1 1kΩ 10%
1
GAIN TRIM
1
R2 2kΩ
SIGNAL
INPUT
0V TO +10V
1
R1 AND R2 CAN BE OMITTED IF GAIN TRIM
IS NOT REQUIRED.
08014-015
Figure 15. AD581 as −10 V Reference for CMOS ADC
PNP LOGIC SWITCHES AND LEVEL SHIFTERS
0.1µF
0.1µF
OP1177
OP AMP
OUTPUT
5kΩ
(8kΩ)
A
5kΩ
(8kΩ)
R4
20kΩ, 15T
R3
3.0MΩ
9.950kΩ
(15.95k)
CONTROL
AMP
CONTROL AMP
SUMMING
JUNCTION
100Ω, 15T
R2
GAIN ADJ.
10V
V
OUT
R1
100Ω, 15T
BIPOLAR OFFSET ADJ.
GND
19.95kΩ
0.5mA
–15V
AD565A
+15V
–15V
UNIPOLAR
OFFSET ADJ.
A = ANALOG GROUND
24
BIT 1
(MSB)
23
BIT 2
22
BIT 3
21
BIT 4
20
BIT 5
19
BIT 6
18
BIT 7
17
BIT 8
16
BIT 9
15
BIT 10
14
BIT 11
13
2
3
11
10
9
12
8
7
BIT 12
(LSB)
216
4
5
3
A
–
15
V
+5V/+15
V
+15V
+V
S
AD581
08014-016
Figure 16. Precision 12-Bit DAC