AD589
APPLICATION INFORMATION
+5V
6.2kΩ
+V
COMMON
+5V
6.8kΩ
b. With 7107 Panel Meter A/D
Figure 7. AD589 Used as Reference for CMOS
A/D Converters
AD589
10kΩ
V
OUT
Figure 5. Basic Configuration for 1.2 V or Less
The AD589 can also be used as a building block to generate
other values of reference voltage. Figure 6 shows a circuit which
produces a buffered 10 V output. Total supply current for this
circuit is approximately 2 mA.
AD589
The AD589 also is useful as a reference for CMOS multiplying
DACs such as the AD7533. These DACs require a negative
reference voltage in order to provide a positive output range.
Figure 8 shows the AD589 used to supply an equivalent –1.0 V
reference to an AD7533.
BIT
1
MSB
V
DD
BIT
10
LSB
2
3
4
5
6
7
8
9
AD589
+15V
15kΩ
7
2
6
AD108A
3
4
0.01µF
1kΩ
8
1
1kΩ
10V
+15V
REF
14
15
R1
39kΩ
–15V
R2
5kΩ
GND
3
2
OUT2
AD7533 SERIES
1
OUT1
16
R
FB
V
OUT
=
0 TO 1.00V
AD542L
8.2kΩ
Figure 8. AD589 as Reference for 10-Bit CMOS DAC
Figure 6. Single Supply Buffered 10 V Reference
The low power operation of the AD589 makes it ideal for use in
battery operated portable equipment. It is especially useful as a
reference for CMOS analog-to-digital converters. Figure 7
shows the AD589 used in conjunction with two popular
integrating type CMOS A/D converters.
+5V
5.6kΩ
+V
OUTLINE DIMENSIONS AND PIN DESIGNATIONS
Dimensions shown in inches and (mm).
0.209 (5.31)
DIA
0.230 (5.84)
0.10 (2.54)
0.195 (4.95)
DIA
0.178 (4.52)
0.150 (3.81)
0.125 (3.17)
6.8kΩ
AD589
7109
REF+
REF–
REF OUT
45°
2kΩ
0.028 (0.71)
0.048 (1.22)
0.015 (0.38)
0.019 (0.48)
0.500 (12.7)
MIN
0.036 (0.91)
0.046 (1.17)
a. With 7109 12-Bit Binary A/D
–4–
REV. B
PRINTED IN U.S.A.
C547c–2–7/88
The AD589 functions as a two-terminal shunt-type regulator. It
provides a constant 1.23 V output for a wide range of input
current from 50
µA
to 5 mA. Figure 5 shows the simplest
configuration for an output voltage of 1.2 V or less. Note that
no frequency compensation is required. If additional filtering is
desired for ultralow noise applications, minimum recommended
capacitance is 1000 pF.
10kΩ
AD589
7107
REF HI
REF LO
1kΩ
AD [ ANALOG DEVICES ]
