LTC1250
Very Low Noise
Zero-Drift Bridge Amplifier
FEATURES
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DESCRIPTIO
Very Low Noise: 0.75碌V
P-P
Typ, 0.1Hz to 10Hz
DC to 1Hz Noise Lower Than OP-07
Full Output Swing into 1k Load
Offset Voltage: 10碌V Max
Offset Voltage Drift: 50nV/擄C Max
Common-Mode Rejection Ratio: 110dB Min
Power Supply Rejection Ratio: 115dB Min
No External Components Required
Pin-Compatible with Standard 8-Pin Op Amps
APPLICATI
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The LTC
廬
1250 is a high performance, very low noise zero-
drift operational amplifier. The LTC1250鈥檚 combination of
low front-end noise and DC precision makes it ideal for use
with low impedance bridge transducers. The LTC1250
features typical input noise of 0.75碌V
P-P
from 0.1Hz to
10Hz, and 0.2碌V
P-P
from 0.1Hz to 1Hz. The LTC1250 has
DC to 1Hz noise of 0.35碌V
P-P
, surpassing that of low noise
bipolar parts including the OP-07, OP-77, and LT1012.
The LTC1250 uses the industry-standard single op amp
pinout, and requires no external components or nulling
signals, allowing it to be a plug-in replacement for bipolar
op amps.
The LTC1250 incorporates an improved output stage
capable of driving 4.3V into a 1k load with a single 5V
supply; it will swing
鹵4.9V
into 5k with
鹵5V
supplies. The
input common mode range includes ground with single
power supply voltages above 12V. Supply current is 3mA
with a
鹵5V
supply, and overload recovery times from
positive and negative saturation are 0.5ms and 1.5ms,
respectively. The internal nulling clock is set at 5kHz for
optimum low frequency noise and offset drift; no external
connections are necessary.
The LTC1250 is available in standard 8-pin ceramic and
plastic DIPs, as well as an 8-pin SOIC package.
Electronic Scales
Strain Gauge Amplifiers
Thermocouple Amplifiers
High Resolution Data Acquisition
Low Noise Transducers
Instrumentation Amplifiers
and LTC are registered trademarks and LT is a trademark of Linear Technology Corporation.
TYPICAL APPLICATI
5V
50鈩?/div>
GAIN
TRIM
Differential Bridge Amplifier
5V
1000pF
Input Referred Noise 0.1Hz to 10Hz
2
V
S
= 鹵5V
A
V
= 10k
1
0.1碌F
18.2k
碌V
0
350鈩?/div>
STRAIN
GAUGE
2
鈥?/div>
+
7
6
A
V
= 100
LTC1250
3
4
鈥?
1000pF
鈥?V
18.2k
鈥?V
1250 TA01
鈥?
0
U
2
6
4
TIME (s)
8
10
LT1250 TA02
UO
UO
1
1
2
3
4
5
6
7
8
