Skip to main content

INA2181A3

Current-Sense Amplifier

The INA2181A3 is a current-sense amplifier from Texas Instruments. View the full INA2181A3 datasheet below including electrical characteristics, absolute maximum ratings.

Manufacturer

Texas Instruments

Category

Current-Sense Amplifier

Overview

Part: INAx181 — Texas Instruments

Type: Bidirectional, Low- and High-Side Voltage Output, Current-Sense Amplifiers

Description: The INAx181 family of current-sense amplifiers senses voltage drops across current-sense resistors at common-mode voltages from -0.2 V to +26 V, independent of the supply voltage, and offers fixed-gain options of 20 V/V, 50 V/V, 100 V/V, or 200 V/V.

Operating Conditions:

  • Supply voltage: 2.7 V to 5.5 V
  • Operating temperature: -40 to 125 °C
  • Common-mode input voltage: -0.2 V to 26 V

Absolute Maximum Ratings:

  • Max supply voltage: 6 V
  • Max continuous current: 8 mA (output)
  • Max junction/storage temperature: 150 °C

Key Specs:

  • Offset voltage (VCM = 0 V): ±150 μV (maximum)
  • Offset voltage (VCM = 12 V): ±500 μV (maximum)
  • Offset drift: 1 μV/°C (maximum)
  • Gain error: ±1% (maximum)
  • Common-mode rejection ratio (VCM = 0 V to 26 V): 84 dB (minimum)
  • Bandwidth (A1 devices): 350 kHz
  • Slew rate: 2 V/μs
  • Quiescent current (INA181): 260 μA (maximum)

Features:

  • Common-mode range (VCM): -0.2 V to +26 V
  • High bandwidth: 350 kHz (A1 devices)
  • Bidirectional current-sensing capability
  • Integrated matched resistor gain network

Applications:

  • Motor control
  • Battery monitors and balancers
  • Power management
  • Lighting control
  • Solar inverters

Package:

  • DBV (SOT-23, 6)
  • DCK (SC70, 6)
  • DGS (VSSOP, 10)
  • DSQ (WSON, 10)
  • PW (TSSOP, 20)

Features

  • Common-mode range (VCM): -0.2 V to +26 V
  • High bandwidth: 350 kHz (A1 devices)
  • Offset voltage:
  • -±150 μV (maximum) at VCM = 0 V
  • -±500 μV (maximum) at VCM = 12 V
  • Output slew rate: 2 V/μs
  • Bidirectional current-sensing capability
  • Accuracy:
  • -±1% gain error (maximum)
  • -1-μV/°C offset drift (maximum)
  • Gain options:
  • -20 V/V (A1 devices)
  • -50 V/V (A2 devices)
  • -100 V/V (A3 devices)
  • -200 V/V (A4 devices)
  • Quiescent current: 260 μA maximum (INA181)

Applications

Typical Application Circuit

Typical Application Circuit

INA181, INA2181, INA4181

SBOS793H - APRIL 2017 - REVISED NOVEMBER 2023

Pin Configuration

Figure 5-1. INA181: DBV Package 6-Pin SOT-23 Top View

Table 4-1. Device Comparison

Figure 5-2. INA181: DCK Package 6-Pin SC70 Top View

Table 5-1. Pin Functions: INA181 (Single Channel)

PINPINPINTYPEDESCRIPTION
NAMESOT-23SC70TYPEDESCRIPTION
GND22AnalogGround
IN-45Analog inputCurrent-sense amplifier negative input. For high-side applications, connect to load side of sense resistor. For low-side applications, connect to ground side of sense resistor.
IN+34Analog inputCurrent-sense amplifier positive input. For high-side applications, connect to bus-voltage side of sense resistor. For low-side applications, connect to load side of sense resistor.
OUT16Analog outputOutput voltage
REF51Analog inputReference input
VS63AnalogPower supply, 2.7 V to 5.5 V

Table 5-1. Pin Functions: INA181 (Single Channel)

Figure 5-3. INA2181: DGS Package 10-Pin VSSOP Top View

Figure 5-3. INA2181: DGS Package 10-Pin VSSOP Top View

Figure 5-4. INA2181: DSQ Package 10-Pin WSON Top View

Figure 5-5. INA4181: PW Package 20-Pin TSSOP Top View

Table 5-2. Pin Functions: INA2181 (Dual Channel) and INA4181 (Quad Channel)

PINPINPINTYPEDESCRIPTION
NAMEINA2181INA4181TYPEDESCRIPTION
GND416AnalogGround
IN-123Analog inputCurrent-sense amplifier negative input for Channel 1. For high-side applications, connect to load side of Channel 1 sense resistor. For low-side applications, connect to ground side of Channel 1 sense resistor.
IN+134Analog inputCurrent-sense amplifier positive input for Channel 1. For high-side applications, connect to bus-voltage side of Channel 1 sense resistor. For low-side applications, connect to load side of Channel 1 sense resistor.
IN-287Analog inputCurrent-sense amplifier negative input for Channel 2. For high-side applications, connect to load side of Channel 2 sense resistor. For low-side applications, connect to ground side of Channel 2 sense resistor.
IN+276Analog inputCurrent-sense amplifier positive input for Channel 2. For high-side applications, connect to bus-voltage side of Channel 2 sense resistor. For low-side applications, connect to load side of Channel 2 sense resistor.
IN-3-14Analog inputCurrent-sense amplifier negative input for Channel 3. For high-side applications, connect to load side of Channel 3 sense resistor. For low-side applications, connect to ground side of Channel 3 sense resistor.

Table 5-2. Pin Functions: INA2181 (Dual Channel) and INA4181 (Quad Channel)

Electrical Characteristics

at T A = 25°C, VS = 5 V, V REF = V S / 2, V IN+ = 12 V, and VSENSE = VIN+ - VIN- (unless otherwise noted)

PARAMETERPARAMETERPARAMETERCONDITIONSMINTYPMAXUNIT
INPUTINPUTINPUTINPUTINPUTINPUTINPUTINPUT
CMRRCommon-mode rejection ratio, RTI (1)Common-mode rejection ratio, RTI (1)V IN+ = 0 V to 26 V, V SENSE = 0 mV, T A = -40°C to +125°C84100dB
V OSV SENSE = 0 mV, V IN+ = 0 V±25±150μV
Offset voltage, RTIOffset voltage, RTIV SENSE = 0 mV±100±500μV
dV OS /dTOffset drift, RTIOffset drift, RTIV SENSE = 0 mV, T A = -40°C to +125°C0.21μV/°C
PSRRRTI vs power supply ratioRTI vs power supply ratioV S = 2.7 V to 5.5 V, V IN+ = 12 V, V SENSE = 0 mV±8±40μV/V
I IBV SENSE = 0 mV, V IN+ = 0 V-6μA
Input bias currentInput bias currentV SENSE = 0 mV75μA
I IOInput offset currentInput offset currentV SENSE = 0 mV±0.05μA
OUTPUTOUTPUTOUTPUTOUTPUTOUTPUTOUTPUTOUTPUTOUTPUT
GA1 devices20V/V
GA2 devices50V/V
GGainGainA3 devices100V/V
GA4 devices200V/V
E GGain errorGain errorV OUT = 0.5 V to V S - 0.5 V, T A = -40°C to +125°C±0.1%±1%
Gain error vs temperatureGain error vs temperatureT A = -40°C to +125°C1.520ppm/°C
Nonlinearity errorNonlinearity errorV OUT = 0.5 V to V S - 0.5 V±0.01%
Maximum capacitive loadMaximum capacitive loadNo sustained oscillation1nF
VOLTAGE OUTPUT (2)VOLTAGE OUTPUT (2)VOLTAGE OUTPUT (2)VOLTAGE OUTPUT (2)VOLTAGE OUTPUT (2)VOLTAGE OUTPUT (2)VOLTAGE OUTPUT (2)VOLTAGE OUTPUT (2)
V SPSwing to V S power-supply rail (3)Swing to V S power-supply rail (3)R L = 10 kΩ to GND, T A = -40°C to +125°C(V S ) - 0.02(V S ) - 0.03V
V SNSwing to GND (3)Swing to GND (3)R L = 10 kΩ to GND, T A = -40°C to +125°C(V GND ) + 0.0005(V GND ) + 0.005V
FREQUENCY RESPONSEFREQUENCY RESPONSEFREQUENCY RESPONSEFREQUENCY RESPONSEFREQUENCY RESPONSEFREQUENCY RESPONSEFREQUENCY RESPONSEFREQUENCY RESPONSE
BWA1 devices, C LOAD = 10 pF350kHz
BWA2 devices, C LOAD = 10 pF210kHz
BWBandwidthBandwidthA3 devices, C LOAD = 10 pF
A4 devices, C LOAD = 10 pF
150
105
kHz
kHz
SRSlew rateSlew rate2V/μs
NOISE, RTI (1)NOISE, RTI (1)NOISE, RTI (1)NOISE, RTI (1)NOISE, RTI (1)NOISE, RTI (1)NOISE, RTI (1)NOISE, RTI (1)
Voltage noise densityVoltage noise densityVoltage noise density40nV/√Hz
POWER SUPPLYPOWER SUPPLYPOWER SUPPLYPOWER SUPPLYPOWER SUPPLYPOWER SUPPLYPOWER SUPPLYPOWER SUPPLY
INA181V SENSE = 0 mV
V SENSE = 0 mV, T A = -40°C to +125°C
195260
300
μA
IINA2181V SENSE = 0 mV356500
QV SENSE = 0 mV, T A = -40°C to +125°C520μA
INA4181V SENSE = 0 mV
V SENSE = 0 mV, T A = -40°C to +125°C
690900
1000
μA

Absolute Maximum Ratings

over operating free-air temperature range (unless otherwise noted) (1)

MINMAXUNIT
Supply voltage, V SSupply voltage, V S6V
Analog inputs, IN+, IN- (2)Differential (V IN+ ) - (V IN- )-2626V
Analog inputs, IN+, IN- (2)Common-mode (3)GND - 0.326V
Input voltage rangeat REF pinGND - 0.3V S + 0.3V
Output VoltageOutput VoltageGND - 0.3V S + 0.3V
Maximum output current, I OUTMaximum output current, I OUT8mA
Operating fee-air temperature, T AOperating fee-air temperature, T A-55150°C
Junction temperature, T JJunction temperature, T J150°C
Storage temperature, T stgStorage temperature, T stg-65150°C
  • (1) Operation outside the Absolute Maximum Ratings may cause permanent device damage. Absolute Maximum Ratings do not imply functional operation of the device at these or any other conditions beyond those listed under Recommended Operating Conditions. If used outside the Recommended Operating Conditions but within the Absolute Maximum Ratings, the device may not be fully functional, and this may affect device reliability, functionality, performance, and shorten the device lifetime.
  • (2) VIN+ and VIN- are the voltages at the IN+ and IN- pins, respectively.
  • (3) Input voltage at any pin can exceed the voltage shown if the current at that pin is limited to 5 mA.

Recommended Operating Conditions

over operating free-air temperature range (unless otherwise noted)

MINNOMMAXUNIT
V CMCommon-mode input voltage (IN+ and IN-)-0.21226V
V SOperating supply voltage2.755.5V
T AOperating free-air temperature-40125°C

Thermal Information

INA181INA181INA2181INA2181INA4181
THERMAL METRIC (1)THERMAL METRIC (1)DCK (SC70) 6 PINSDBV (SOT-23)DSQ (WSON)DGS (VSSOP)PW (TSSOP)
Junction-to-ambient thermal resistance6 PINS10 PINS10 PINS14 PINS
R θJA188.0198.774.5177.397.0
R θJC(top)Junction-to-case (top) thermal resistance140.8120.989.768.737.7
R θJBJunction-to-board thermal resistance78.852.339.898.448.3
ψ JTJunction-to-top characterization parameter62.130.33.712.63.6
ψ JBJunction-to-board characterization parameter78.552.039.796.947.9
R θJC(bot)Junction-to-case (bottom) thermal resistanceN/AN/A16.8N/AN/A

Typical Application

The INAx181 amplify the voltage developed across a current-sensing resistor as current flows through the resistor to the load or ground. The ability to drive the reference pin to adjust the functionality of the output signal offers multiple configurations, as discussed in previous sections.

Package Information

PART NUMBERPACKAGE (1)PACKAGE SIZE (2)
INA181DBV (SOT-23, 6)2.90 mm × 2.80 mm
INA181DCK (SC70, 6)2.00 mm × 2.10 mm
INA2181DGS (VSSOP, 10)3.00 mm × 4.90 mm
INA2181DSQ (WSON, 10)2.00 mm × 2.00 mm
INA4181PW (TSSOP, 20)6.50 mm × 6.40 mm
  • (1) For all available packages, see Section 11.
  • (2) The package size (length × width) is a nominal value and includes pins, where applicable.

Related Variants

The following components are covered by the same datasheet.

Part NumberManufacturerPackage
INA181Texas InstrumentsDBV (SOT-23, 6)
INA181-Q1Texas Instruments
INA181A1Texas Instruments
INA181A2Texas Instruments
INA181A3Texas Instruments
INA181A4Texas Instruments
INA2181A1Texas Instruments
INA2181A2Texas Instruments
INA2181A4Texas Instruments
INA4181A1Texas Instruments
INA4181A2Texas Instruments
INA4181A3Texas Instruments
INA4181A4Texas Instruments
INAX181Texas Instruments
Data on this page is extracted from publicly available manufacturer datasheets using automated tools including AI. It may contain errors or omissions. Always verify specifications against the official manufacturer datasheet before making design or purchasing decisions. See our Terms of Service. Rights holders can submit a takedown request.

Get structured datasheet data via API

Get started free