Datasheet

11
LTC1051/LTC1053
10513fa
–
+
–
+
–
+
A
B
1/2
LTC1051
1/2
LTC1051
A1
R1
R2
1
1
2
2
3
3
OUT
OUT
R3
R4
R5
C1
C2
5
6
6
7
8
5V
+
–
1051/53 AC01a
A1 R1 R2 R3 R4 R5 C1 C2 e
OUT
(DC – 1Hz)** e
OUT
(DC – 10Hz)**
LT1007 3k 2k 340k 10k 100k 0.01µF 0.001µF 0.1µV
P-P
0.15µV
P-P
LT1012* 750Ω 57Ω 250k 10k 100k 0.01µF 0.001µF 0.3µV
P-P
0.4µV
P-P
Obtaining Ultralow V
OS
Drift and Low Noise
The dual chopper op amp buffers the inputs of A1 and
corrects its offset voltage and offset voltage drift. With the
R, C values shown, the power-up warm up time is typically
20 seconds. The step response of the composite amplifier
does not present settling tails. The LT1007 should be used
when extremely low noise; V
OS
and V
OS
drift are sought
when the input source resistance is low—for instance a
350Ω strain gauge bridge. The LT1012 or equivalent
should be used when low bias current (100pA) is also
required in conjunction with DC to 10Hz low noise and low
V
OS
and V
OS
drift. The measured typical input offset
voltages were less than 2µV.
V
S
= ±5V
DC TO 10Hz
NOISE
1 SEC/DIV
0.2µV/DIV
1051/53 AC01b
DC TO 1Hz
NOISE
LTC1051/LT1007 Peak-to-Peak Noise
TYPICAL APPLICATIO S
U
* Interchange connections A and B .
** Noise measured in a 10 sec window. Peak-to-peak noise was also measured for 10 continuous minutes: With the LT1007 op amp the recorded noise was less than 0.2µV
P-P
for both DC-1Hz
and DC-10Hz.