1

LT1168

Low Power, Single

Resistor Gain Programmable,

Precision Instrumentation Amplifier

TheLT

plifier that requires only one external resistor to set gains of

1 to 10,000. The low voltage noise of 10nV/

√Hz (at 1kHz) is

notcompromisedbylowpowerdissipation(350

µAtypicalfor

±15Vsupplies).Thewidesupplyrangeof±2.3Vto±18Vallows

the LT1168 to fit into a wide variety of industrial as well as

battery-powered applications.

ThehighaccuracyoftheLT1168isduetoa20ppmmaximum

nonlinearityand0.4%maxgainerror(G=10).Previousmono-

lithic instrumentation amps cannot handle a 2k load resistor

whereas the nonlinearity of the LT1168 is specified for loads

as low as 2k. The LT1168 is laser trimmed for very low input

offsetvoltage(40

µVmax),drift(0.3µV/°C),highCMRR(90dB,

G = 1) and PSRR (103dB, G = 1). Low input bias currents of

250pA max are achieved with the use of superbeta process-

ing. 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 LT1168 with two external 5k

resistors passes the IEC 1000-4-2 level 4 specification.

The LT1168 is a pin-for-pin improved second source for the

AD620 and INA118. The LT1168, offered in 8-pin PDIP and

SO packages, requires significantly less PC board area than

discrete op amp resistor designs. These advantages make

the LT1168 the most cost effective solution for precision

instrumentation amplifier applications.

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Supply Current: 530

µA Max

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Meets IEC 1000-4-2 Level 4 (

±15kV) ESD Tests

with Two External 5k Resistors

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Single Gain Set Resistor: G = 1 to 10,000

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Gain Error: G = 10, 0.4% Max

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Input Offset Voltage Drift: 0.3

µV/°C Max

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Gain Nonlinearity: G = 10, 20ppm Max

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Input Offset Voltage: 40

µV Max

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Input Bias Current: 250pA Max

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Wide Supply Range:

±2.3V to ±18V

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1kHz Voltage Noise: 10nV/

√Hz

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0.1Hz to 10Hz Noise: 0.28

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Available in 8-Pin PDIP and SO Packages

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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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Differential Voltage to Current Converters

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Data Acquisition

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Battery-Powered and Portable Equipment

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Medical Instrumentation

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Scales

, LTC and LT are registered trademarks of Linear Technology Corporation.

Single Supply* Pressure Monitor

G = 1000

OUTPUT VOLTAGE (2V/DIV)

1168 TA01a

Gain Nonlinearity

*See Theory of Operation section

FEATURES

DESCRIPTIO

APPLICATIO S

TYPICAL APPLICATIO

–

+

2

3

2

1

1

1

1/2

LT1112

3.5k

5V

3.5k

3.5k

3.5k

8

7

6

1168 TA01

5

40k

20k

40k

DIGITAL

DATA

OUTPUT

4

R1

G = 200

249

Ω

3

REF

IN

AGND

ADC

LTC

BI TECHNOLOGIES

67-8-3 R40KQ, (0.02% RATIO MATCH)

–

+

LT1168