INA351 Cost and Size Optimized, Low Power, 1.8V to 5.5V Selectable Gain

Instrumentation Amplifier with Integrated Reference Buffer

1 Features

• Designed for size, cost, and power conscious

applications

• Selectable gain options with integrated reference

buffer

– G = 10 or G = 20 (INA351ABS)

– G = 30 or G = 50 (INA351CDS)

• Space saving ultra-small package options

– 10-pin X2QFN (RUG) – 3mm2

– 8-pin WSON (DSG) – 4mm2

– 8-pin SOT23-THN (DDF) – 4.64mm2

• Optimized performance for 10-bit to 14-bit systems

– CMRR: 95dB (typical) across all gains

– Offset voltage: 0.2mV (typical) across all gains

– Gain error (typical):

• 0.015% for G = 10, G = 50

• 0.020% for G = 20, G = 30

• Bandwidth: 100kHz for G = 10 (typical)

• Drives 500pF with less than 20% overshoot

(typical)

• Optimized quiescent current: 110µA (typical)

• Shutdown option for power conscious applications

• Supply range: 1.8V (±0.9V) to 5.5V (±2.75V)

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

2 Applications

• Bridge network sensing

• Differential to single-ended conversion

• Weigh scale

• Analog input module

• Flow transmitter

• Wearable fitness and activity monitor

• Blood glucose monitor

• Pressure and temperature sensing

+

–

+

–

+

–

60 k

60 k

60 k

60 k

REF

V+

OUT

V

IN

+IN

2

3

4

5

6

7

90 k

/ 145 k

90 k

/ 145 k

RG

GS

1

SHDN

8

_____

Note: 90kΩ for INA351ABS and 145kΩ for INA351CDS

Simplified Internal Schematic

3 Description

The INA351 is a selectable-gain instrumentation

amplifier with integrated reference buffer that offers

four gain options across the INA351ABS and

INA351CDS variants available in small packages. The

INA351ABS has gain options of 10 or 20 and the

INA351CDS has gain options of 30 or 50. These

gain options can be selected by toggling the gain

select (GS) pin. The INA351 is an excellent choice

for bridge-type sensing and for differential to single-

ended conversion applications.

Built with precision matched integrated resistors, the

INA351 saves on BOM costs, pick-and-place machine

handling costs, and board space by removing the

need for precise or closely-matched external resistors.

The INA351 can interface directly to low-speed,

10-bit to 14-bit, analog-to-digital converters (ADCs)

and is an excellent choice for replacing discrete

implementation of instrumentation amplifiers built with

commodity amplifiers and discrete resistors.

Designed with the three-amplifier architecture, the

INA351 is optimized for delivering performance. The

device achieves 86dB of minimum CMRR and an

accurate 0.1% of maximum gain error, along with

1.3mV of maximum offset across all gain options,

while consuming just 135µA of maximum quiescent

current. The INA351 has an integrated shutdown

option to turn off the amplifier when idle for additional

power savings in battery-powered applications.

Package Information

PART NUMBER(1)

PACKAGE(2)

PACKAGE SIZE (3)

INA351ABS

DSG (WSON, 8)

2mm × 2mm

DDF (SOT-23, 8)

1.6mm × 2.9mm

RUG (X2QFN, 10)

1.5mm × 2 mm

INA351CDS

DSG (WSON, 8)

2mm × 2mm

DDF (SOT-23, 8)

1.6mm × 2.9mm

RUG (X2QFN, 10)

1.5mm × 2mm

(1)

See Section 4

(2)

For more information, see Section 11.

(3)

The package size (length × width) is a nominal value and

includes pins, where applicable.

INA351

SBOSAD5D – DECEMBER 2022 – REVISED NOVEMBER 2024

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.