LT1920
Single Resistor Gain
Programmable, Precision
Instrumentation Amplifier
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DESCRIPTIO
FEATURES
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The LT ®1920 is a low power, precision instrumentation
amplifier that requires only one external resistor to set gains
of 1 to 10,000. The low voltage noise of 7.5nV/√Hz (at 1kHz)
is not compromised by low power dissipation (0.9mA typical
for ±2.3V to ±15V supplies).
The high accuracy of 30ppm maximum nonlinearity and
0.3% max gain error (G = 10) is not degraded even for load
resistors as low as 2k (previous monolithic instrumentation
amps used 10k for their nonlinearity specifications). The
LT1920 is laser trimmed for very low input offset voltage
(125µV max), drift (1µV/°C), high CMRR (75dB, G = 1) and
PSRR (80dB, G = 1). Low input bias currents of 2nA max are
achieved with the use of superbeta processing. The output
can handle capacitive loads up to 1000pF in any gain configuration while the inputs are ESD protected up to 13kV (human
body). The LT1920 with two external 5k resistors passes the
IEC 1000-4-2 level 4 specification.
The LT1920, offered in 8-pin PDIP and SO packages, is a pin
for pin and spec for spec improved replacement for the
AD620. The LT1920 is the most cost effective solution for
precision instrumentation amplifier applications. For even
better guaranteed performance, see the LT1167.
Single Gain Set Resistor: G = 1 to 10,000
Gain Error: G = 10, 0.3% Max
Gain Nonlinearity: G = 10, 30ppm Max
Input Offset Voltage: G = 10, 225µV Max
Input Offset Voltage Drift: 1µV/°C Max
Input Bias Current: 2nA Max
PSRR at G = 1: 80dB Min
CMRR at G = 1: 75dB Min
Supply Current: 1.3mA Max
Wide Supply Range: ± 2.3V to ±18V
1kHz Voltage Noise: 7.5nV/√Hz
0.1Hz to 10Hz Noise: 0.28µVP-P
Available in 8-Pin PDIP and SO Packages
Meets IEC 1000-4-2 Level 4 ESD Tests with
Two External 5k Resistors
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APPLICATIO S
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Bridge Amplifiers
Strain Gauge Amplifiers
Thermocouple Amplifiers
Differential to Single-Ended Converters
Medical Instrumentation
, LTC and LT are registered trademarks of Linear Technology Corporation.
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TYPICAL APPLICATIO
Single Supply Barometer
VS
2
2
–
4
1
–
4
5k
R6
1k
R1
825Ω
5k
2
5
6
R8
100k
+
7
+
3
6
LT1920
G = 60
8
3
5
TO
4-DIGIT
DVM
4
5
1/2
LT1490
–
R2
12Ω
5k
RSET
R3
50k
2
1
5k
6
R4
50k
VS
1
NONLINEARITY (100ppm/DIV)
1/2
LT1490
1
LT1634CCZ-1.25
LUCAS NOVA SENOR
NPC-1220-015-A-3L
8
+
+
3
Gain Nonlinearity
–
R5
392k
OUTPUT VOLTAGE (2V/DIV)
G = 1000
RL = 1k
VOUT = ±10V
7
R7
50k
VS = 8V TO 30V
VOLTS
2.800
3.000
3.200
INCHES Hg
28.00
30.00
32.00
1167 TA02
1920 TA01
1
