Datasheet

8
LT1002
1002fb
TYPICAL PERFORMANCE CHARACTERISTICS
U
W
LOAD RESISTANCE (Ω)
100 300
OUTPUT SWING (VOLTS)
16
12
8
4
0
1000 3k 10k
1002 G28
V
S
= ±15V
T
A
= 25°C
POSITIVE SWING
NEGATIVE SWING
TIME FROM OUTPUT SHORT (MINUTES)
0
SHORT CIRCUIT CURRENT (mA)
SINKING SOURCING
2
50
40
30
20
10
–10
–20
–30
–40
–50
1002 G29
134
–55°C
–55°C
25°C
25°C
125°C
125°C
V
S
= ±15V
Output Short Circuit Current
vs Time
Output Swing vs. Load Resistance
APPLICATIONS INFORMATION
WUU
U
The LT1002 dual amplifier may be inserted directly into
OP-10, OP207, OP227 sockets with or without removal of
external nulling potentiometers.
Offset Voltage Adjustment The input offset voltage of the
LT1002, and its drift with temperature, are permanently
trimmed at wafer testing to a low level. However, if further
adjustment of V
OS
is necessary, nulling with a 10k or 20k
potentiometer will not degrade drift with temperature.
Trimming to a value other than zero creates a drift of (V
OS
/
300)µV/°C, e.g. if V
OS
is adjusted to 300µV, the change in
drift will be 1µV/°C. The adjustment range with a 10k or
20k pot is approximately ±2.5mV. If less adjustment
range is needed, the sensitivity and resolution of the
nulling can be improved by using a smaller pot in conjunc-
tion with fixed resistors. The example has an approximate
null range of ±100µV.
In matching applications, both amplifiers can be trimmed
to zero, or the offset of one amplifier can be trimmed to
match the offset of the other. Offset adjustment, however,
slightly degrades the gain, common-mode and power-
supply rejection match between the two op amps. Fortu-
nately, the guaranteed offset voltage match of the LT1002
is very low, in most applications offset adjustment will be
unnecessary.
Improved Sensitivity Adjustment
Standard Adjustment
–
+
–15V
1/2
LT1002
15V
3
(10)
(11)
4
(9)
(8)
13 (6)
14 (7)
OUTPUT
INPUT
1002 TA03
12 (5)
2
10k
or
20k
1
–
+
–15V
1/2
LT1002
15V
3
(10)
(11)
4
(9)
(8)
13 (6)
14
OUTPUT
INPUT
1002 TA04
12 (5)
2
1k
7.5k
7.5k
1
(7)