Data Sheet
AD588
APPLICATIONS INFORMATION
The AD588 can be configured to provide +10 V and –10 V
reference outputs, as shown in Figure 4 and Figure 6, respectively.
It can also be used to provide +5 V, −5 V, or a 5 V tracking
reference, as shown in Figure 5. Table 5 details the appropriate
pin connections for each output range. In each case, Pin 9 is
connected to system ground, and power is applied to Pin 2
and Pin 16.
Amplifier A3 and Amplifier A4 can be used interchangeably.
However, the AD588 is tested (and the specifications are
guaranteed) with the amplifiers connected, as indicated in
Figure 4 and Table 5. When either A3 or A4 is unused, its
output force and sense pins should be connected or the input
tied to ground.
Two outputs of the same voltage can be obtained by connecting
both A3 and A4 to the appropriate unbuffered output on Pin 6,
Pin 8, or Pin 11. Performance in these dual-output configurations
typically meets data sheet specifications.
The architecture of the AD588 provides ground sense and
uncommitted output buffer amplifiers that offer the user a great
deal of functional flexibility. The AD588 is specified and tested
in the configurations shown in Figure 6. The user can choose to
take advantage of the many other configuration options available
with the AD588. However, performance in these configurations
is not guaranteed to meet the extremely stringent data sheet
specifications.
CALIBRATION
Generally, the AD588 meets the requirements of a precision
system without additional adjustment. Initial output voltage
error of 1 mV and output noise specs of 10 µV p-p allow for
accuracies of 12 bits to 16 bits. However, in applications where
an even greater level of accuracy is required, additional calibra-
tion may be called for. Provision for trimming has been made
through the use of the GAIN ADJ and BAL ADJ pins (Pin 5 and
Pin 12, respectively).
As indicated in Table 5, a +5 V buffered output can be provided
using Amplifier A4 in the +10 V configuration (Figure 4). A
−5 V buffered output can be provided using Amplifier A3 in the
−10 V configuration (Figure 6). Specifications are not guaranteed
for the +5 V or −5 V outputs in these configurations. Performance
is similar to that specified for the +10 V or −10 V outputs.
The AD588 provides a precision 10 V span with a center tap
(VCT) that is used with the buffer and ground sense amplifiers to
achieve the voltage output configurations in Table 5. GAIN ADJ
and BAL ADJ can be used in any of these configurations to trim
the magnitude of the span voltage and the position of the center
tap within the span. The gain adjust should be performed first.
Although the trims are not interactive within the device, the
gain trim moves the balance trim point as it changes the
magnitude of the span.
As indicated in Table 5, unbuffered outputs are available at
Pin 6, Pin 8, and Pin 11. Loading of these unbuffered outputs
impairs circuit performance.
Table 5. Pin Connections
Connect
Pin 10 to Pin
8
Unbuffered1 Output on Pins
−10 V −5 V 0 V +5 V +10 V
Buffered Output
Connections
Buffered Output on Pins
Range
−10 V
−5 V 0 V +5 V +10 V
+10 V
8
11
6
11 to 13, 1± to 15,
6 to ±, and 3 to 1
8 to 13, 1± to 15,
6 to ±, and 3 to 1
8 to 13, 1± to 15,
11 to ±, and 3 to 1
6 to ± and 3 to 1
8 to 13 and 1± to 15
15
1
−5 V or +5 V
−10 V
11
6
8
11
6
6
15
1
8
11
15
1
+5 V
−5 V
11
11
6
1
8
15
1 Unbuffered outputs should not be loaded.
Rev. M | Page 7 of 20
ADI [ ADI ]
