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INA121

International Airport Industrial Park • Mailing Address: PO Box 11400, Tucson, AZ 85734 • Street Address: 6730 S. Tucson Blvd., Tucson, AZ 85706 • Tel: (520) 746-1111 • Twx: 910-952-1111

Internet: http://www.burr-brown.com/ • FAXLine: (800) 548-6133 (US/Canada Only) • Cable: BBRCORP • Telex: 066-6491 • FAX: (520) 889-1510 • Immediate Product Info: (800) 548-6132

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INA121

INA121

INA121

PDS-1412A

Printed in U.S.A. May, 1998

FEATURES

q LOW BIAS CURRENT:

q LOW QUIESCENT CURRENT:

q LOW INPUT OFFSET VOLTAGE:

q LOW INPUT OFFSET DRIFT:

q LOW INPUT NOISE:

20nV/

√Hz at f = 1kHz (G =100)

q HIGH CMR: 106dB

q WIDE SUPPLY RANGE:

q LOW NONLINEARITY ERROR: 0.001% max

q INPUT PROTECTION TO

q 8-PIN DIP AND SO-8 SURFACE MOUNT

FET-Input, Low Power

INSTRUMENTATION AMPLIFIER

DESCRIPTION

The INA121 is a FET-input, low power instrumenta-

tion amplifier offering excellent accuracy. Its versatile

three-op amp design and very small size make it ideal

for a variety of general purpose applications. Low bias

current (

±4pA) allows use with high impedance

sources.

Gain can be set from 1V to 10,000V/V with a single

external resistor. Internal input protection can with-

stand up to

±40V without damage.

The INA121 is laser-trimmed for very low offset

voltage (

±200µV), low offset drift (±2µV/°C), and

high common-mode rejection (106dB at G = 100). It

operates on power supplies as low as

±2.25V (+4.5V),

allowing use in battery operated and single 5V sys-

tems. Quiescent current is only 450

µA.

Package options include 8-pin plastic DIP and SO-8

surface mount. All are specified for the –40

°C to

+85

°C industrial temperature range.

APPLICATIONS

q LOW-LEVEL TRANSDUCER AMPLIFIERS

Bridge, RTD, Thermocouple

q PHYSIOLOGICAL AMPLIFIERS

ECG, EEG, EMG, Respiratory

q HIGH IMPEDANCE TRANSDUCERS

q CAPACITIVE SENSORS

q MULTI-CHANNEL DATA ACQUISITION

q PORTABLE, BATTERY OPERATED SYSTEMS

q GENERAL PURPOSE INSTRUMENTATION

A

1

A

2

A

3

6

40k

Ω

40k

Ω

40k

Ω

40k

Ω

7

4

3

8

1

2

V

IN

V

IN

R

G

V+

V–

INA121

Ref

V

O

G = 1 +

50k

Ω

R

G

–

+

5

Over-Voltage

Protection

25k

Ω

25k

Ω

Over-Voltage

Protection

SBOS078