INA2181A2
Current-Sense AmplifierThe INA2181A2 is a current-sense amplifier from Texas Instruments. View the full INA2181A2 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)
| PIN | PIN | PIN | TYPE | DESCRIPTION |
|---|---|---|---|---|
| NAME | SOT-23 | SC70 | TYPE | DESCRIPTION |
| GND | 2 | 2 | Analog | Ground |
| IN- | 4 | 5 | Analog input | Current-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+ | 3 | 4 | Analog input | Current-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. |
| OUT | 1 | 6 | Analog output | Output voltage |
| REF | 5 | 1 | Analog input | Reference input |
| VS | 6 | 3 | Analog | Power 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)
| PIN | PIN | PIN | TYPE | DESCRIPTION |
|---|---|---|---|---|
| NAME | INA2181 | INA4181 | TYPE | DESCRIPTION |
| GND | 4 | 16 | Analog | Ground |
| IN-1 | 2 | 3 | Analog input | Current-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+1 | 3 | 4 | Analog input | Current-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-2 | 8 | 7 | Analog input | Current-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+2 | 7 | 6 | Analog input | Current-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 | - | 14 | Analog input | Current-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)
| PARAMETER | PARAMETER | PARAMETER | CONDITIONS | MIN | TYP | MAX | UNIT |
|---|---|---|---|---|---|---|---|
| INPUT | INPUT | INPUT | INPUT | INPUT | INPUT | INPUT | INPUT |
| CMRR | Common-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°C | 84 | 100 | dB | |
| V OS | V SENSE = 0 mV, V IN+ = 0 V | ±25 | ±150 | μV | |||
| Offset voltage, RTI | Offset voltage, RTI | V SENSE = 0 mV | ±100 | ±500 | μV | ||
| dV OS /dT | Offset drift, RTI | Offset drift, RTI | V SENSE = 0 mV, T A = -40°C to +125°C | 0.2 | 1 | μV/°C | |
| PSRR | RTI vs power supply ratio | RTI vs power supply ratio | V S = 2.7 V to 5.5 V, V IN+ = 12 V, V SENSE = 0 mV | ±8 | ±40 | μV/V | |
| I IB | V SENSE = 0 mV, V IN+ = 0 V | -6 | μA | ||||
| Input bias current | Input bias current | V SENSE = 0 mV | 75 | μA | |||
| I IO | Input offset current | Input offset current | V SENSE = 0 mV | ±0.05 | μA | ||
| OUTPUT | OUTPUT | OUTPUT | OUTPUT | OUTPUT | OUTPUT | OUTPUT | OUTPUT |
| G | A1 devices | 20 | V/V | ||||
| G | A2 devices | 50 | V/V | ||||
| G | Gain | Gain | A3 devices | 100 | V/V | ||
| G | A4 devices | 200 | V/V | ||||
| E G | Gain error | Gain error | V OUT = 0.5 V to V S - 0.5 V, T A = -40°C to +125°C | ±0.1% | ±1% | ||
| Gain error vs temperature | Gain error vs temperature | T A = -40°C to +125°C | 1.5 | 20 | ppm/°C | ||
| Nonlinearity error | Nonlinearity error | V OUT = 0.5 V to V S - 0.5 V | ±0.01% | ||||
| Maximum capacitive load | Maximum capacitive load | No sustained oscillation | 1 | nF | |||
| 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 SP | Swing 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 ) - 0.03 | V | |
| V SN | Swing 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 ) + 0.005 | V | |
| FREQUENCY RESPONSE | FREQUENCY RESPONSE | FREQUENCY RESPONSE | FREQUENCY RESPONSE | FREQUENCY RESPONSE | FREQUENCY RESPONSE | FREQUENCY RESPONSE | FREQUENCY RESPONSE |
| BW | A1 devices, C LOAD = 10 pF | 350 | kHz | ||||
| BW | A2 devices, C LOAD = 10 pF | 210 | kHz | ||||
| BW | Bandwidth | Bandwidth | A3 devices, C LOAD = 10 pF A4 devices, C LOAD = 10 pF | 150 105 | kHz kHz | ||
| SR | Slew rate | Slew rate | 2 | V/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 density | Voltage noise density | Voltage noise density | 40 | nV/√Hz | |||
| POWER SUPPLY | POWER SUPPLY | POWER SUPPLY | POWER SUPPLY | POWER SUPPLY | POWER SUPPLY | POWER SUPPLY | POWER SUPPLY |
| INA181 | V SENSE = 0 mV V SENSE = 0 mV, T A = -40°C to +125°C | 195 | 260 300 | μA | |||
| I | INA2181 | V SENSE = 0 mV | 356 | 500 | |||
| Q | V SENSE = 0 mV, T A = -40°C to +125°C | 520 | μA | ||||
| INA4181 | V SENSE = 0 mV V SENSE = 0 mV, T A = -40°C to +125°C | 690 | 900 1000 | μA |
Absolute Maximum Ratings
over operating free-air temperature range (unless otherwise noted) (1)
| MIN | MAX | UNIT | ||
|---|---|---|---|---|
| Supply voltage, V S | Supply voltage, V S | 6 | V | |
| Analog inputs, IN+, IN- (2) | Differential (V IN+ ) - (V IN- ) | -26 | 26 | V |
| Analog inputs, IN+, IN- (2) | Common-mode (3) | GND - 0.3 | 26 | V |
| Input voltage range | at REF pin | GND - 0.3 | V S + 0.3 | V |
| Output Voltage | Output Voltage | GND - 0.3 | V S + 0.3 | V |
| Maximum output current, I OUT | Maximum output current, I OUT | 8 | mA | |
| Operating fee-air temperature, T A | Operating fee-air temperature, T A | -55 | 150 | °C |
| Junction temperature, T J | Junction temperature, T J | 150 | °C | |
| Storage temperature, T stg | Storage temperature, T stg | -65 | 150 | °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)
| MIN | NOM | MAX | UNIT | ||
|---|---|---|---|---|---|
| V CM | Common-mode input voltage (IN+ and IN-) | -0.2 | 12 | 26 | V |
| V S | Operating supply voltage | 2.7 | 5 | 5.5 | V |
| T A | Operating free-air temperature | -40 | 125 | °C |
Thermal Information
| INA181 | INA181 | INA2181 | INA2181 | INA4181 | ||
|---|---|---|---|---|---|---|
| THERMAL METRIC (1) | THERMAL METRIC (1) | DCK (SC70) 6 PINS | DBV (SOT-23) | DSQ (WSON) | DGS (VSSOP) | PW (TSSOP) |
| Junction-to-ambient thermal resistance | 6 PINS | 10 PINS | 10 PINS | 14 PINS | ||
| R θJA | 188.0 | 198.7 | 74.5 | 177.3 | 97.0 | |
| R θJC(top) | Junction-to-case (top) thermal resistance | 140.8 | 120.9 | 89.7 | 68.7 | 37.7 |
| R θJB | Junction-to-board thermal resistance | 78.8 | 52.3 | 39.8 | 98.4 | 48.3 |
| ψ JT | Junction-to-top characterization parameter | 62.1 | 30.3 | 3.7 | 12.6 | 3.6 |
| ψ JB | Junction-to-board characterization parameter | 78.5 | 52.0 | 39.7 | 96.9 | 47.9 |
| R θJC(bot) | Junction-to-case (bottom) thermal resistance | N/A | N/A | 16.8 | N/A | N/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 NUMBER | PACKAGE (1) | PACKAGE SIZE (2) |
|---|---|---|
| INA181 | DBV (SOT-23, 6) | 2.90 mm × 2.80 mm |
| INA181 | DCK (SC70, 6) | 2.00 mm × 2.10 mm |
| INA2181 | DGS (VSSOP, 10) | 3.00 mm × 4.90 mm |
| INA2181 | DSQ (WSON, 10) | 2.00 mm × 2.00 mm |
| INA4181 | PW (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 Number | Manufacturer | Package |
|---|---|---|
| INA181 | Texas Instruments | DBV (SOT-23, 6) |
| INA181-Q1 | Texas Instruments | — |
| INA181A1 | Texas Instruments | — |
| INA181A2 | Texas Instruments | — |
| INA181A3 | Texas Instruments | — |
| INA181A4 | Texas Instruments | — |
| INA2181A1 | Texas Instruments | — |
| INA2181A3 | Texas Instruments | — |
| INA2181A4 | Texas Instruments | — |
| INA4181A1 | Texas Instruments | — |
| INA4181A2 | Texas Instruments | — |
| INA4181A3 | Texas Instruments | — |
| INA4181A4 | Texas Instruments | — |
| INAX181 | Texas Instruments | — |
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