LT1920
Single Resistor Gain
Programmable, Precision
Instrumentation Amplifier
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DESCRIPTIO
FEATURES
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)
isnotcompromisedbylowpowerdissipation(0.9mAtypical
for ±2.3V to ±15V supplies).
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Single Gain Set Resistor: G = 1 to 10,000
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Gain Error: G = 10, 0.3% Max
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Gain Nonlinearity: G = 10, 30ppm Max
Input Offset Voltage: G = 10, 225µV Max
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Input Offset Voltage Drift: 1µV/°C Max
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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
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
canhandlecapacitiveloadsupto1000pFinanygainconfigu-
ration 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.
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APPLICATIO S
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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.
Bridge Amplifiers
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Strain Gauge Amplifiers
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Thermocouple Amplifiers
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Differential to Single-Ended Converters
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Medical Instrumentation
, LTC and LT are registered trademarks of Linear Technology Corporation.
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TYPICAL APPLICATIO
Single Supply Barometer
V
S
Gain Nonlinearity
R5
LUCAS NOVA SENOR
NPC-1220-015-A-3L
V
S
392k
3
2
8
+
–
1
3
–
+
2
1
–
1
7
1/2
LT1490
4
1
2
5k
5k
LT1634CCZ-1.25
R1
4
6
825Ω
LT1920
G = 60
R6
1k
R2
12Ω
5k
2
6
5k
5
8
3
TO
+
4-DIGIT
DVM
R
4
R4
50k
SET
5
6
5
+
–
OUTPUT VOLTAGE (2V/DIV)
G = 1000
R3
50k
7
1/2
LT1490
R
OUT
= 1k
L
V
= ±10V
1167 TA02
R7
50k
R8
100k
VOLTS INCHES Hg
2.800
3.000
3.200
28.00
30.00
32.00
V
= 8V TO 30V
S
1920 TA01
1