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Texas Instruments INA2181A2IDGST
- Part No.:
- INA2181A2IDGST
- Manufacturer:
- Texas Instruments
- Category:
- Instrumentation, Op Amps, Buffer Amps
- Package:
- 10-TFSOP, 10-MSOP (0.118", 3.00mm Width)
- Datasheet:
-
INA2181A2IDGST.pdf
- Description:
- IC CURR SENSE 2 CIRCUIT 10VSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:977
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Product details
Overview
INA2181A2IDGST from Texas Instruments is a dual-channel, bidirectional current-sense amplifier with 50 V/V fixed gain, –0.2 V to +26 V input common-mode range, ±500 µV max offset at 12 V VCM, and 210 kHz small-signal bandwidth - designed for high-accuracy motor control and battery monitoring in industrial power systems.
For engineers reviewing the INA2181A2IDGST datasheet, INA2181A2IDGST pinout, INA2181A2IDGST application, or INA2181A2IDGST equivalent, this page delivers verified specifications, dual-channel pin mapping, real-world use cases in bidirectional current sensing, and validated alternative options for supply continuity and design flexibility.
Technical Context
The INA2181A2IDGST implements a precision current-shunt monitor architecture with matched internal gain resistors (50 V/V), enabling accurate RTI voltage measurement across sense resistors independent of supply voltage. Its differential input stage supports both high-side and low-side configurations without external level-shifting circuitry.
It operates from a single 2.7–5.5 V supply, draws ≤500 µA quiescent current over –40°C to +125°C, and features rail-to-rail output swing (≤30 mV from VS, ≤5 mV from GND) with 2 V/µs slew rate - optimized for fast transient response in closed-loop motor drives and fault-detection circuits.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Gain | 50 V/V - fixed, factory-trimmed ratio enabling direct conversion of shunt voltage to scaled output without external resistors. |
| Common-mode range | –0.2 V to +26 V - allows sensing on bus voltages far exceeding supply (e.g., 24-V motor rails powered by 3.3-V logic). |
| Offset voltage | ±500 µV max at VCM = 12 V - ensures <1% error down to ~10 mV shunt drop, supporting low-RSENSE designs. |
| Bandwidth | 210 kHz - sufficient for PWM-based motor current sampling at up to ~10 kHz switching frequencies with minimal phase lag. |
| Supply current | 500 µA max - enables dual-channel sensing in battery-powered or thermally constrained applications. |
| Output swing | VS – 30 mV / GND + 5 mV - maximizes dynamic range for ADC interfacing with 12-bit+ resolution. |
| Gain error | ±1% max - guarantees absolute current measurement accuracy without per-unit calibration. |
Pinout & Package
INA2181A2IDGST is housed in a 10-pin VSSOP package (DGS), 3.0 mm × 4.9 mm, with exposed thermal pad (optional GND connection). Pin functions are electrically isolated per channel and support independent reference biasing.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| OUT1, OUT2 | Analog output | Amplified, bidirectional current-sense outputs referenced to respective REF pins; each drives 10-kΩ load to rail. |
| IN+1, IN+2 | Positive input | Connect to high-potential side of sense resistor (bus side for high-side, load side for low-side). |
| IN–1, IN–2 | Negative input | Connect to low-potential side of sense resistor (load side for high-side, ground side for low-side). |
| REF1, REF2 | Reference input | DC bias point setting zero-current output level; 0 V → unidirectional, VS/2 → bidirectional full-scale swing. |
| VS | Power supply | Single 2.7–5.5 V analog supply; decoupling capacitor required at pin. |
| GND | Analog ground | Return path for all analog signals; must be star-connected to minimize noise coupling between channels. |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional sensing | Enabled via REF pin biasing - supports regenerative braking current flow detection in motor drives without polarity reversal hardware. |
| Matched gain network | Factory-trimmed 50 V/V ratio minimizes inter-channel gain mismatch (<0.1%) for differential current measurement in dual-motor or phase-current applications. |
| Rail-to-rail output | Delivers >99% of supply range to ADC - eliminates need for external level-shifting or gain staging in 3.3-V microcontroller interfaces. |
| High CMRR | 84–100 dB over –40°C to +125°C - rejects bus-voltage transients during MOSFET switching, critical for stable current readouts in noisy inverters. |
| Low quiescent current | 500 µA max for two channels - reduces self-heating and enables always-on battery monitoring in energy-harvesting systems. |
Applications
| Motor Control | Battery Monitoring |
|---|---|
Use Scenario: Real-time phase current sensing in BLDC motor drives using low-side shunts with 20-kHz PWM switching. IC Role / Device Role / Timing Role: Dual-channel current-shunt monitor providing synchronized, bidirectional current outputs for field-oriented control (FOC) algorithms. Use Value: 210 kHz bandwidth and 2 V/µs slew rate ensure accurate capture of current ripple; ±500 µV offset enables <1% error at 10-A peak with 1-mΩ shunt. | Use Scenario: Cell-level current monitoring in 48-V Li-ion battery packs with active balancing and charge/discharge state tracking. IC Role / Device Role / Timing Role: Dual-channel amplifier measuring bidirectional pack current and individual module current for SOC/SOH estimation. Use Value: –0.2 V to +26 V common-mode range accommodates pack voltage swings during load dump; 500 µA IQ extends standby runtime. |
| Solar Inverters | Lighting Control |
Use Scenario: DC-link current sensing in string inverters with MPPT tracking and anti-islanding protection. IC Role / Device Role / Timing Role: High-side current monitor on PV input bus operating at up to 1000 VDC (via isolated sense resistor). Use Value: 26 V common-mode capability enables direct interface to isolated shunt amplifiers; ±1% gain error ensures precise power calculation for grid compliance. | Use Scenario: LED driver current regulation in smart street lighting with dimming feedback and thermal derating. IC Role / Device Role / Timing Role: Low-side current monitor feeding analog input of MCU for closed-loop constant-current control. Use Value: 50 V/V gain and rail-to-rail output deliver full-scale ADC range from 0.1-A to 10-A loads; 125°C rating supports outdoor enclosure operation. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar current-sense amplifier applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| INA2181A1IDGST | 20 V/V gain, 350 kHz bandwidth, ±150 µV max offset at 0 V VCM | Better low-current accuracy at near-ground common-mode; lower gain requires larger shunt or post-amplification for same output swing. | Select when sensing sub-ampere currents with minimal shunt voltage drop and high bandwidth is prioritized over dynamic range. |
| INA240A2IDR | 50 V/V gain, 400 kHz bandwidth, –4 V to +80 V common-mode, higher PSRR (110 dB) | Supports higher bus voltages and harsher EMI environments; wider VCM enables direct high-side sensing on 48-V/60-V systems without isolation. | Choose for automotive or industrial applications requiring extended common-mode range and enhanced noise immunity beyond 26 V. |
Compared with INA2181A1IDGST, the INA2181A2IDGST trades bandwidth for higher gain and relaxed offset spec at mid-range VCM, better suiting medium-current motor and battery applications; versus INA240A2IDR, it offers lower cost and smaller footprint but lacks extended VCM and automotive qualification.
Availability
INA2181A2IDGST is available at Aetrix Electronics and suitable for motor control, battery monitoring, and solar inverter designs requiring stable component supply, dual-channel synchronization, and production-grade temperature performance.
Supply support for INA2181A2IDGST includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Texas Instruments is a global semiconductor leader delivering analog, embedded processing, and connectivity solutions for industrial, automotive, and communications markets.
The INA2181 belongs to TI's precision current-sense amplifier product line, engineered for cost-optimized, high-accuracy bidirectional current measurement in power-constrained and thermally demanding applications.
FAQ
What is the maximum common-mode voltage supported by the INA2181A2IDGST?
The INA2181A2IDGST supports a common-mode input voltage range from –0.2 V to +26 V, independent of its 2.7–5.5 V supply voltage. This allows direct high-side sensing on 24-V industrial buses without level-shifting circuitry. The specification is guaranteed across the full –40°C to +125°C operating temperature range, as confirmed in Section 6.3 of the SBOS793H datasheet.
Does the INA2181A2IDGST require external gain-setting resistors?
No, the INA2181A2IDGST integrates a factory-trimmed 50 V/V gain network internally. No external resistors are needed for basic operation - simplifying layout, reducing component count, and eliminating resistor tolerance and drift errors. Gain is fixed and cannot be adjusted; alternate variants (A1/A3/A4) offer 20/100/200 V/V if different scaling is required.
How does the INA2181A2IDGST enable bidirectional current sensing?
The INA2181A2IDGST achieves bidirectional sensing by biasing the REF1 and REF2 pins to a midpoint voltage (e.g., VS/2). When current flows in one direction, OUT1/OUT2 rise above REF; reverse current pulls outputs below REF. Equation 1 in the datasheet (VOUT = ILOAD × RSENSE × GAIN + VREF) defines this linear relationship - enabling true signed-current measurement with a single-supply ADC.
What is the thermal performance of the INA2181A2IDGST in its VSSOP package?
In the 10-pin VSSOP (DGS) package, the INA2181A2IDGST has a junction-to-ambient thermal resistance (RθJA) of 177.3°C/W and junction-to-board (RθJB) of 98.4°C/W, per Section 6.4 of SBOS793H. With ≤500 µA supply current, self-heating is minimal (<0.1°C at 25°C ambient), making thermal derating unnecessary in most PCB layouts with standard copper pour.
Can the two channels of the INA2181A2IDGST be used independently with different reference voltages?
Yes - REF1 and REF2 are separate pins, allowing independent biasing. For example, Channel 1 can be configured for unidirectional sensing (REF1 = 0 V) while Channel 2 monitors bidirectional current (REF2 = VS/2). This flexibility supports mixed-sensing topologies, such as motor phase current (bidirectional) and supply rail current (unidirectional) in the same system using a single INA2181A2IDGST.
INA2181A2IDGST Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 10-TFSOP, 10-MSOP (0.118", 3.00mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Amplifier Type:
- Current Sense
- Number of Circuits:
- 2
- Output Type:
- Rail-to-Rail
- Slew Rate:
- 2V/µs
- Gain Bandwidth Product:
- -
- -3db Bandwidth:
- 210 kHz
- Current - Input Bias:
- 75 µA
- Voltage - Input Offset:
- 100 µV
- Current - Supply:
- 356µA
- Current - Output / Channel:
- -
- Voltage - Supply Span (Min):
- 2.7 V
- Voltage - Supply Span (Max):
- 5.5 V
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 10-VSSOP
INA2181A2IDGST FAQ
1.How can I place an order for INA2181A2IDGST through Aetrix?
Please submit a Request for Quotation (RFQ) for INA2181A2IDGST on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for INA2181A2IDGST reliable?
The price and inventory of INA2181A2IDGST are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for INA2181A2IDGST is usually 5 days.
3.What payment methods are accepted for INA2181A2IDGST?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for INA2181A2IDGST transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for INA2181A2IDGST?
INA2181A2IDGST orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your INA2181A2IDGST order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for INA2181A2IDGST?
For technical support, including INA2181A2IDGST datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your INA2181A2IDGST requirements.
6.How does Aetrix verify that INA2181A2IDGST is sourced from the original manufacturer or authorized distributors?
All INA2181A2IDGST products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that INA2181A2IDGST meets industry standards.
7.What is the process for return or replacement of INA2181A2IDGST?
All INA2181A2IDGST units undergo pre-shipment inspection (PSI). If there is an issue with INA2181A2IDGST, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The INA2181A2IDGST part is unused and in its original packaging.
Return procedure for INA2181A2IDGST:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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