Datasheet

AD584 Data Sheet
Rev. C | Page 10 of 12
The AD584 is normally used in the −10 V mode with the AD7574
to give a 0 V to +10 V ADC range. This is shown in Figure 17.
Bipolar output applications and other operating details can be
found in the data sheets for the CMOS products.
Figure 17. AD584 as −10 V Reference for CMOS ADC
PRECISION DAC REFERENCE
The AD565A, like many DACs, can operate with an external
10 V reference element (see Figure 19). This 10 V reference
voltage is converted into a reference current of approximately
0.5 mA via the internal 19.95 kΩ resistor (in series with the external
100 Ω trimmer). The gain temperature coefficient of the AD565A
is primarily governed by the temperature tracking of the 19.95 kΩ
resistor and the 5 kΩ/10 kΩ span resistors; this gain temperature
coefficient is guaranteed to 3 ppm/°C. Therefore, using the AD584K
(at 5 ppm/°C) as the 10 V reference guarantees a maximum full-
scale temperature coefficient of 18 ppm/°C more than the
commercial range. The 10 V reference also supplies the normal
1 mA bipolar offset current through the 9.95 kΩ bipolar offset
resistor. The bipolar offset temperature coefficient thus depends
only on the temperature coefficient matching of the bipolar offset
resistor to the input reference resistor and is guaranteed to
3 ppm/°C. Figure 18 demonstrates the flexibility of the AD584
applied to another popular digital-to-analog configuration.
Figure 18. Current Output, 8-Bit Digital-to-Analog Configuration
Figure 19. Precision 12-Bit DAC
–10V REF
AD584
4
1
8
–15V
V+
10.0V
COMMON
R3
1.2kΩ
5%
0.1µF
+15V
1 18
2
3
4
5
AD7574
(TOP VIEW)
SIGNAL
INPUT
0V TO +10V
ANALOG
GROUND
GROUND
INTERTIE
DIGITAL
SUPPLY
RETURN
R1
2kΩ 10%*
*R1 AND R2 CAN BE OMITTED IF
GAIN TRIM IS NOT REQUIRED.
GAIN TRIM
R2 2kΩ*
00527-019
C
A1 (MSB) 5
14
A2 6
15
A3 7
A4 8
A5 9
A6 10
A7 11
4
I
O
A8 (LSB) 12
COMP 16
1 V
LC
R
L
R15
R14 = R15
V+
13
V–
3
2
AD
DAC08
V
REF
(+)
V
REF
(–)
AD584
4
8
1
3
COMMON
V+
2.5V
10.0V
R14
00527-020
I
OUT
00527-018
0.5mA
I
REF
DAC
AD565A
5kΩ
20V SPAN
10V SPAN
DAC OUT
–V
EE
REF
GND
BIPOLAR OFF
5kΩ
8kΩI
O
CODE INPUT
LSBMSB
10V
V
CC
REF OUT
REF
IN
POWER
GND
19.95kΩ
20kΩ
9.95kΩ
I
OUT
=
4 × I
REF
× CODE
0.1µF
0.1µF
OP1177
+15V
–15V
2
3
6
OP AMP
OUTPUT
±10V
+15V
+15V
1
4
8
AD584
R2
100Ω
15T
GAIN
ADJUST
R1
100Ω
15T
BIPOLAR OFFSET
ADJUST
–15V