Datasheet
AD588
Rev. L | Page 8 of 20
Figure 5 shows gain and balance trims in a +5 V and −5 V
tracking configuration. A 100 kΩ, 20-turn potentiometer
is used for each trim. The potentiometer for gain trim is
connected between Pin 6 (V
HIGH
) and Pin 8 (V
LOW
) with the
wiper connected to Pin 5 (GAIN ADJ). The potentiometer is
adjusted to produce exactly 10 V between Pin 1 and Pin 15, the
amplifier outputs. The balance potentiometer, also connected
between Pin 6 and Pin 8 with the wiper to Pin 12 (BAL ADJ), is
then adjusted to center the span from +5 V to −5 V.
Trimming in other configurations works in exactly the same
manner. When producing +10 V and +5 V, GAIN ADJ is used
to trim +10 V and BAL ADJ is used to trim +5 V. In the −10 V
and −5 V configuration, GAIN ADJ is again used to trim the
magnitude of the span, −10 V, while BAL ADJ is used to trim
the center tap, −5 V.
Trimming the AD588 introduces no additional errors over
temperature, so precision potentiometers are not required. For
single-output voltage ranges, or in cases when balance adjust is
not required, Pin 12 should be connected to Pin 11. If gain
adjust is not required, Pin 5 should be left floating.
In single output configurations, GAIN ADJ is used to trim
outputs utilizing the full span (+10 V or −10 V), while BAL ADJ
is used to trim outputs using half the span (+5 V or −5 V).
Input impedance on both the GAIN ADJ and BAL ADJ pins is
approximately 150 kΩ. The GAIN ADJ trim network effectively
attenuates the 10 V across the trim potentiometer by a factor of
about 1500 to provide a trim range of −3.5 mV to +7.5 mV with
a resolution of approximately 550 V/turn (20-turn potentiome-
ter). The BAL ADJ trim network attenuates the trim voltage by
a factor of about 1400, providing a trim range of ±4.5 mV with
resolution of 450 µV/turn.
R3
R
B
R1
R2
R4
R5
R6
–V
S
+V
S
A1
A4
AD588
A3
SYSTEM
GROUND
+10V
+15V
+5V
–15V
SYSTEM
GROUND
0.1µF
0.1µF
00531-004
1
14
15
2
16
13111281095
346
7
A2
Figure 4. +10 V Output
R3
R
B
R1
R2
R4
R5
R6
–V
S
+V
S
A1
A4
AD588
A3
A2
SYSTEM
GROUND
+5V
+15V
–5V
–15V
SYSTEM
GROUND
0.1µF
0.1µF
100kΩ
20T
BALANCE
ADJUST
100kΩ
20T
GAIN ADJUST
+15V
NOISE
REDUCTION
1µF
00531-005
39kΩ
Figure 5. +5 V and −5 V Outputs
R3
R
B
R1
R2
R4
R5
R6
–V
S
+V
S
A1
A4
AD588
A3
SYSTEM
GROUND
+15V
–10V
–15V
SYSTEM
GROUND
0.1µF
0.1µF
NOISE
REDUCTION
–5V
0.1µF
0.1µF
00531-006
1
14
15
2
16
3467
13111281095
A2
Figure 6. −10 V Output