LTC1250_05 Datasheet, PDF (1/12 Pages) Linear Technology – Very Low Noise Zero-Drift Bridge Amplifier

FEATURES
■ _{Very Low Noise: 0.75µVP-P Typ, 0.1Hz to 10Hz}
■ _{DC to 1Hz Noise Lower Than OP-07}
■ _{Full Output Swing into 1k Load}
■ _{Offset Voltage: 10µV Max}
■ _{Offset Voltage Drift: 50nV/°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}
■ _{Available in Standard 8-Pin Plastic DIP}
and 8-Pin SO Packages
U
APPLICATIO S
■ _{Electronic Scales}
■ _{Strain Gauge Amplifiers}
■ _{Thermocouple Amplifiers}
■ _{High Resolution Data Acquisition}
■ _{Low Noise Transducers}
■ _{Instrumentation Amplifiers}
, LTC and LT are registered trademarks of Linear Technology Corporation. All other
trademarks are the property of their respective owners. Protected by U.S. Patents
including 4933642.
LTC1250
Very Low Noise
Zero-Drift Bridge Amplifier
DESCRIPTIO
The LTC^®1250 is a high performance, very low noise zero-
drift operational amplifier. The LTC1250’s 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 0.75µV_P-P from 0.1Hz to
10Hz, and 0.2µV_P-P from 0.1Hz to 1Hz. The LTC1250 has
DC to 1Hz noise of 0.35µV_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 ±4.9V into 5k with ±5V supplies. The
input common mode range includes ground with single
power supply voltages above 12V. Supply current is 3mA
with a ±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 a standard 8-pin plastic DIP
and 8-pin SO packages.
TYPICAL APPLICATIO
Differential Bridge Amplifier
5V
5V
50Ω
GAIN
TRIM
0.1µF
1000pF
18.2k
350Ω
STRAIN
GAUGE
2_– 7
LTC1250
6
3₊
4
1000pF _18.2k
–5V
–5V
A_V = 100
1250 TA01
Input Referred Noise 0.1Hz to 10Hz
2
V_S = ±5V
A_V = 10k
1
0
–1
–2
0
2
4
6
8
10
TIME (s)
LT1250 TA02
1250fb
1