LT1037 Linear Technology Corporation, LT1037 Datasheet - Page 9

• Manufacturer Part Number: LT1037
• Description: Low Noise, High Speed Precision Operational Amplifiers
• Manufacturer: Linear Technology Corporation

APPLICATIONS
General
The LT1007/LT1037 series devices may be inserted
directly into OP-07, OP-27, OP-37 and 5534 sockets with
or without removal of external compensation or nulling
components. In addition, the LT1007/LT1037 may be
fitted to 741 sockets with the removal or modification of
external nulling components.
Offset Voltage Adjustment
The input offset voltage of the LT1007/LT1037 and its drift
with temperature, are permanently trimmed at wafer
testing to a low level. However, if further adjustment of
V
will not degrade drift with temperature. Trimming to a
value other than zero creates a drift of (V
e.g., if V
1 V/ C (Figure 1).
The adjustment range with a 10k pot is approximately
and resolution of the nulling can be improved by using a
smaller pot in conjunction with fixed resistors. The ex-
ample has an approximate null range of
(Figure 2).
OS
2.5mV. If less adjustment range is needed, the sensitivity
is necessary, the use of a 10k nulling potentiometer
OS
is adjusted to 300 V, the change in drift will be
Figure 2. Improved Sensitivity Adjustment
INPUT
Figure 1. Standard Adjustment
U
4.7k
2
3
2
3
–
+
–
+
LT1007
LT1037
LT1007
LT1037
1
1
INFORMATION
–15V
–15V
U
1k
4.7k
8
4
10k
8
4
7 6
7
6
W
15V
15V
1007/37 F02
OUTPUT
1007/37 F01
OUTPUT
OS
/ 300) V/ C,
U
200 V
Offset Voltage and Drift
Thermocouple effects, caused by temperature gradients
across dissimilar metals at the contacts to the input
terminals, can exceed the inherent drift of the amplifier
unless proper care is exercised. Air currents should be
minimized, package leads should be short, the two input
leads should be close together and maintained at the same
temperature.
The circuit shown to measure offset voltage is also used
as the burn-in configuration for the LT1007/LT1037, with
the supply voltages increased to 20V (Figure 3).
Unity-Gain Buffer Application (LT1007 Only)
When R
signal pulse (>1V), the output waveform will look as
shown in the pulsed operation diagram (Figure 4).
During the fast feedthrough-like portion of the output, the
input protection diodes effectively short the output to the
input and a current, limited only by the output short-circuit
protection, will be drawn by the signal generator. With
R
requirements (I
in its active mode and a smooth transition will occur.
F
500 , the output is capable of handling the current
+
–
F
Figure 3. Test Circuit for Offset Voltage and
Offset Voltage Drift with Temperature
100 and the input is driven with a fast, large-
R
F
100 *
50k*
LT1007
L
2
3
Figure 4. Pulsed Operation
–
+
20mA at 10V) and the amplifier stays
LT1007
LT1037
50k*
–15V
15V
4
OUTPUT
7
*RESISTORS MUST HAVE LOW
V
THERMOELECTRIC POTENTIAL
OUT
6
LT1007/LT1037
= 1000V
V
OS
OUT
1007/37 F03
sn100737 100737fbs
2.8V/ s
1007/37 F04
9