Input Stage Offset Voltage Drift (PV/qC)

-0.4

-0.3

-0.2

-0.1

0

0.1

0.2

0.3

0.4

30

25

20

15

10

5

0

D002

+

±

+

±

+

±

10 k

24.7 k

10 k

10 k

10 k

24.7 k

Over-

Voltage

Protection

Over-

Voltage

Protection

RG

REF

+VS

OUT

-VS

-IN

+IN

RG

O

IN

IN

REF

V

G V

V

V

:

G

49.4 k

G

1

R

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Folder

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An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,

intellectual property matters and other important disclaimers. PRODUCTION DATA.

INA821

SBOS893D – AUGUST 2018 – REVISED JUNE 2020

INA821 35-µV Offset, 7-nV/

√Hz Noise, Low-Power, Precision Instrumentation Amplifier

1

1 Features

1

•

Low offset voltage: 10 µV (typ), 35 µV (max)

•

Gain drift: 5 ppm/°C (G = 1),

35 ppm/°C (G > 1) (max)

•

Noise: 7 nV/

√Hz

•

Bandwidth: 4.7 MHz (G = 1), 290 kHz (G = 100)

•

Stable with 1-nF capacitive loads

•

Inputs protected up to ±40 V

•

Common-mode rejection: 112 dB, G = 10 (min)

•

Power supply rejection: 110 dB, G = 1 (min)

•

Supply current: 650 µA (max)

•

Supply range:

–

Single-supply: 4.5 V to 36 V

–

Dual-supply: ±2.25 V to ±18 V

•

Specified temperature range: –40°C to +125°C

•

Packages: 8-pin SOIC, VSSOP, and WSON

2 Applications

•

Analog input module

•

Flow transmitter

•

Battery test

•

LCD test

•

Electrocardiogram (ECG)

•

Surgical equipment

•

Process analytics (pH, gas, concentration, force

and humidity)

3 Description

The INA821 is a high-precision instrumentation

amplifier that offers low power consumption and

operates over a wide single-supply or dual-supply

range. A single external resistor sets any gain from 1

to 10,000. The device has high precision as a result

of super-beta input transistors, which provide low

input offset voltage, offset voltage drift, input bias

current,

and

input

voltage

and

current

noise.

Additional

circuitry

protects

the

inputs

against

overvoltage up to ±40 V.

The INA821 is optimized to provide a high common-

mode rejection ratio. At G = 1, the common-mode

rejection ratio exceeds 92 dB across the full input

common-mode range. The device is designed for low-

voltage operation from a 4.5-V single supply, and

dual supplies up to ±18 V.

The INA821 is available in 8-pin SOIC, VSSOP, and

WSON packages, and is specified over the –40°C to

+125°C temperature range.

Device Information(1)

PART NUMBER

PACKAGE

BODY SIZE (NOM)

INA821

SOIC (8)

4.90 mm × 3.91 mm

VSSOP (8)

3.00 mm × 3.00 mm

WSON (8)

3.00 mm x 3.00 mm

(1) For all available packages, see the package option addendum

at the end of the data sheet.

INA821 Simplified Internal Schematic

Typical Distribution of Input Stage Offset Voltage

Drift