Product details

Number of channels 1 Vs (min) (V) 4 Vs (max) (V) 36 CMRR (min) (dB) 90 Common-mode input low (min) (V) -275 Common-mode input high (max) (V) 275 Input offset (±) (max) (V) 0.0011 Iq (typ) (mA) 0.81 Slew rate (typ) (V/µs) 5 Voltage gain (min) (V/V) 1 Voltage gain (max) (V/V) 1 Small-signal bandwidth (typ) (Hz) 500000 Rating Catalog Operating temperature range (°C) -40 to 125 Gain drift (max) (ppm/°C) 10 Gain error (±) (max) (%) 0.02
Number of channels 1 Vs (min) (V) 4 Vs (max) (V) 36 CMRR (min) (dB) 90 Common-mode input low (min) (V) -275 Common-mode input high (max) (V) 275 Input offset (±) (max) (V) 0.0011 Iq (typ) (mA) 0.81 Slew rate (typ) (V/µs) 5 Voltage gain (min) (V/V) 1 Voltage gain (max) (V/V) 1 Small-signal bandwidth (typ) (Hz) 500000 Rating Catalog Operating temperature range (°C) -40 to 125 Gain drift (max) (ppm/°C) 10 Gain error (±) (max) (%) 0.02
SOIC (D) 8 29.4 mm² 4.9 x 6
  • Common-Mode Voltage Range: ±275 V
  • Minimum CMRR: 90 dB from –40°C to +125°C
  • DC Specifications:
    • Maximum Offset Voltage: 1100 µV
    • Maximum Offset Voltage Drift: 15 µV/°C
    • Maximum Gain Error: 0.02%
    • Maximum Gain Error Drift: 10 ppm/°C
    • Maximum Gain Nonlinearity: 0.001% FSR
  • AC Performance:
    • Bandwidth: 500 kHz
    • Typical Slew Rate: 5 V/µs
  • Wide Supply Range: ±2.0 V to ±18 V
    • Maximum Quiescent Current: 900 µA
    • Output Swing on ±15-V Supplies: ±13.5 V
  • Input Protection:
    • Common-Mode: ±500 V
    • Differential: ±500 V
  • Common-Mode Voltage Range: ±275 V
  • Minimum CMRR: 90 dB from –40°C to +125°C
  • DC Specifications:
    • Maximum Offset Voltage: 1100 µV
    • Maximum Offset Voltage Drift: 15 µV/°C
    • Maximum Gain Error: 0.02%
    • Maximum Gain Error Drift: 10 ppm/°C
    • Maximum Gain Nonlinearity: 0.001% FSR
  • AC Performance:
    • Bandwidth: 500 kHz
    • Typical Slew Rate: 5 V/µs
  • Wide Supply Range: ±2.0 V to ±18 V
    • Maximum Quiescent Current: 900 µA
    • Output Swing on ±15-V Supplies: ±13.5 V
  • Input Protection:
    • Common-Mode: ±500 V
    • Differential: ±500 V

The INA149 is a precision unity-gain difference amplifier with a very high input common-mode voltage range. It is a single, monolithic device that consists of a precision op amp and an integrated thin-film resistor network. The INA149 can accurately measure small differential voltages in the presence of common-mode signals up to ±275 V. The INA149 inputs are protected from momentary common-mode or differential overloads of up to 500 V.

In many applications, where galvanic isolation in not required, the INA149 can replace isolation amplifiers. This ability can eliminate costly isolated input side power supplies and the associated ripple, noise, and quiescent current. The excellent 0.0005% nonlinearity and 500-kHz bandwidth of the INA149 are superior to those of conventional isolation amplifiers.

The INA149 is pin-compatible with the INA117 and INA148 type high common-mode voltage amplifiers and offers improved performance over both devices. The INA149 is available in the SOIC-8 package with operation specified over the extended industrial temperature range of –40°C to +125°C.

The INA149 is a precision unity-gain difference amplifier with a very high input common-mode voltage range. It is a single, monolithic device that consists of a precision op amp and an integrated thin-film resistor network. The INA149 can accurately measure small differential voltages in the presence of common-mode signals up to ±275 V. The INA149 inputs are protected from momentary common-mode or differential overloads of up to 500 V.

In many applications, where galvanic isolation in not required, the INA149 can replace isolation amplifiers. This ability can eliminate costly isolated input side power supplies and the associated ripple, noise, and quiescent current. The excellent 0.0005% nonlinearity and 500-kHz bandwidth of the INA149 are superior to those of conventional isolation amplifiers.

The INA149 is pin-compatible with the INA117 and INA148 type high common-mode voltage amplifiers and offers improved performance over both devices. The INA149 is available in the SOIC-8 package with operation specified over the extended industrial temperature range of –40°C to +125°C.

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Technical documentation

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Type Title Date
* Data sheet High Common Mode Voltage Difference Amplifier datasheet (Rev. B) 30 Jul 2012
E-book Tips and tricks for designing with voltage references (Rev. A) 07 May 2021
Application note How to Select Precision Amplifiers for Semiconductor Testers (Rev. A) PDF | HTML 03 Dec 2020
E-book Simplifying Current Sensing (Rev. A) 09 Jan 2020
Circuit design High common-mode differential input voltage to ±10-V ADC input circuit 20 Dec 2018
E-book The Signal e-book: A compendium of blog posts on op amp design topics 28 Mar 2017
Technical article Understanding voltage references: level shift of precision voltage references 15 May 2015
More literature A High-Voltage Bidirectional Current Source 19 Dec 2013
Technical article What you need to know about CMRR- The instrumentation amplifier (part 2) 29 Oct 2013
Technical article Difference Amplifiers—the need for well-matched resistors 25 Apr 2012
EVM User's guide INA149EVM User's Guide 15 Nov 2011

Design & development

For additional terms or required resources, click any title below to view the detail page where available.

Evaluation board

ADS8686SEVM-PDK — ADS8686S 16-channel 16-bit 1-MSPS dual simultaneous-sampling ADC performance demonstration kit (PDK)

The ADS8686S evaluation module (EVM) performance demonstration kit (PDK) is a platform for evaluating the ADS8686S dual simultaneous-sampling analog-to-digital converter (ADC) with an integrated analog front end (AFE).

ADS8686SEVM-PDK includes the ADS8686SEVM board and a precision host interface (...)

User guide: PDF
Evaluation board

DIP-ADAPTER-EVM — DIP adapter evaluation module

Speed up your op amp prototyping and testing with the DIP adapter evaluation module (DIP-ADAPTER-EVM), which provides a fast, easy and inexpensive way to interface with small surface-mount ICs. You can connect any supported op amp using the included Samtec terminal strips or wire them (...)

User guide: PDF
Not available on TI.com
Evaluation board

INA149EVM — INA149 Evaluation Module

The INA149EVM is a platform for basic functional evaluation of the INA149 High Common-Mode Difference Amplifier

User guide: PDF
Not available on TI.com
Simulation model

INA149 PSpice Model

SBOMC47.ZIP (77 KB) - PSpice Model
Simulation model

INA149 TINA-TI Linear Operation Checker

SBOMBK9.TSC (38 KB) - TINA-TI Spice Model
Simulation model

INA149 TINA-TI Reference Design

SBOM667.TSC (164 KB) - TINA-TI Reference Design
Simulation model

INA149 TINA-TI Spice Model

SBOM668.ZIP (9 KB) - TINA-TI Spice Model
Simulation tool

PSPICE-FOR-TI — PSpice® for TI design and simulation tool

PSpice® for TI is a design and simulation environment that helps evaluate functionality of analog circuits. This full-featured, design and simulation suite uses an analog analysis engine from Cadence®. Available at no cost, PSpice for TI includes one of the largest model libraries in the (...)
Simulation tool

TINA-TI — SPICE-based analog simulation program

TINA-TI provides all the conventional DC, transient and frequency domain analysis of SPICE and much more. TINA has extensive post-processing capability that allows you to format results the way you want them. Virtual instruments allow you to select input waveforms and probe circuit nodes voltages (...)
User guide: PDF
Reference designs

TIDA-00439 — Shunt Based Ground Fault Protection for Inverters Powered from 100/110Vac Supply Reference Design

This is a reference design for detecting ground fault in inverter-based drives. Inverter current is measured on both DC-positive and DC-negative bus using shunt resistors. INA149 current sense amplifier having a common-mode voltage range of +275 V is used to measure current on DC-positive bus. (...)
Design guide: PDF
Schematic: PDF
Reference designs

TIDA-01333 — 8-ch Isolated High Voltage Analog Input Module with ISOW7841 Reference Design

The TIDA-01333 isolated high voltage analog input module reference design has eight channels supporting both, voltage and current measurement. In addition, 4 channels support common-mode voltages up to ±160V. Isolation of +5V line and the Serial Peripheral Interface  (SPI) (...)
Design guide: PDF
Schematic: PDF
Reference designs

TIDA-00764 — 8-ch Isolated High Voltage Analog Input Module Reference Design

This reference design is a high-voltage analog input module with eight channels. Each channel can be used for both voltage and current measurement. The design uses 16-bit analog-to-digital converter (ADC) ADS8681 that can handle input voltage of up to ±12.288 V. This make any (...)
Design guide: PDF
Schematic: PDF
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