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Texas Instruments INA381A4IDGSR
- Part No.:
- INA381A4IDGSR
- Manufacturer:
- Texas Instruments
- Category:
- Current Regulation/Management
- Package:
- 10-TFSOP, 10-MSOP (0.118", 3.00mm Width)
- Datasheet:
-
INA381A4IDGSR.pdf
- Description:
- IC CURRENT SENSE 1% 10VSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:9,041
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Product details
Overview
INA381A4IDGSR from Texas Instruments is a 26-V, high-speed current-sense amplifier with integrated comparator and fixed gain of 200 V/V, designed for overcurrent protection in high-side and low-side shunt monitoring. It operates from 2.7 V to 5.5 V supply, supports –0.2 V to +26 V common-mode input range, delivers <10 µs total system overcurrent response time, and is used in DC/DC converters and BLDC motor drives.
For engineers reviewing the INA381A4IDGSR datasheet, INA381A4IDGSR pinout, INA381A4IDGSR application, or INA381A4IDGSR equivalent, this page provides verified technical context, package mapping, real-world use cases, and validated alternative options for precision current monitoring and fast fault detection in industrial and power electronics systems.
Technical Context
The INA381A4IDGSR implements a zero-drift topology for ultra-low offset (≤150 µV at 0 V CM, ≤500 µV at 12 V CM) and minimal drift (1 µV/°C), enabling accurate measurement of small shunt voltages across wide temperature (–40°C to +125°C) and common-mode ranges. Its integrated open-drain comparator features 50 mV hysteresis and 400 ns propagation delay, supporting both transparent and latched alert modes via the RESET pin.
It combines analog signal conditioning (200× gain, 105 kHz bandwidth, 2 V/µs slew rate) with digital fault signaling in a single WSON-8 package. The device tolerates 26 V on IN+/IN– even with no supply applied, and draws only 350 µA max quiescent current - making it suitable for always-on, low-power, high-reliability current monitoring.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Gain | 200 V/V - sets full-scale output swing for 10 mV shunt voltage to 2 V, enabling direct interface with 3.3 V ADCs without attenuation. |
| Common-mode input range | –0.2 V to +26 V - supports high-side sensing on 24 V bus rails and low-side sensing near ground, independent of 2.7–5.5 V supply. |
| Offset voltage (max) | ±500 µV at 12 V CM - limits worst-case error to ±0.25% of full-scale output when measuring 10 mV across shunt at 12 V common-mode. |
| Bandwidth | 105 kHz - captures fast current transients in BLDC motor commutation or PSU overcurrent events without phase lag. |
| Comparator propagation delay | 400 ns (typ) - enables sub-microsecond fault detection, critical for protecting MOSFETs in high-frequency switching applications. |
| Total overcurrent response time | <10 µs - includes amplifier settling + comparator decision, allowing system-level shutdown before destructive energy accumulates. |
| Supply current (max) | 350 µA - enables integration into battery-backed or energy-harvesting subsystems without significant power penalty. |
Pinout & Package
The INA381A4IDGSR is housed in an 8-pin WSON package (2.00 mm × 2.00 mm) with exposed thermal pad tied to GND. This thermally enhanced, space-constrained package supports high-density PCB layouts and efficient heat dissipation in compact power modules.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| IN+ | Analog input (non-inverting) | Connects to supply side of shunt resistor; accepts up to +26 V common-mode voltage regardless of VS. |
| IN– | Analog input (inverting) | Connects to load side of shunt resistor; differential input measures VSENSE = VIN+ – VIN–. |
| VOUT | Analog output | Amplified output: VOUT = 200 × (VIN+ – VIN–); rail-to-rail swing within 50 mV of GND and VS. |
| ALERT | Digital output (open-drain) | Active-low fault indicator; requires external pull-up; asserts within <10 µs of overcurrent event. |
| RESET | Digital input | Selects alert mode: pulled high = transparent; pulled low = latched; internal 100 kΩ pull-down ensures default behavior. |
| CMPIN | Analog input (comparator) | Accepts VOUT or filtered version; compared against CMPREF to trigger ALERT. |
| CMPREF | Analog input (reference) | Sets overcurrent threshold voltage; externally sourced (e.g., REF3140) or resistive divider. |
| GND | Ground reference | System ground connection; thermal pad must be soldered to PCB ground plane for thermal and electrical integrity. |
Key Features
| Feature | Design Value |
|---|---|
| Zero-drift architecture | Enables ≤150 µV offset at 0 V CM and 1 µV/°C drift, reducing calibration burden and improving accuracy over temperature. |
| Integrated comparator with hysteresis | 50 mV built-in hysteresis prevents chatter near threshold; eliminates need for external Schmitt trigger or RC filtering. |
| Alert mode flexibility | Transparent or latched operation selected via RESET pin - supports both real-time monitoring and fault capture in safety-critical systems. |
| High common-mode tolerance | Withstands –0.2 V to +26 V on IN+/IN– pins with no supply applied - simplifies hot-swap and fault-isolation design. |
| Low quiescent current | Max 350 µA draw allows continuous monitoring in always-on subsystems without compromising battery life or thermal budget. |
Applications
| Merchant DC/DC Converters | DC-Input BLDC Motor Drives |
|---|---|
|
Use Scenario: Real-time output current monitoring and overcurrent shutdown in isolated 12 V/48 V telecom and server DC/DC modules. IC Role / Device Role / Timing Role: Current-sense amplifier and comparator jointly provide <10 µs fault detection and latchable alert for primary-side MOSFET protection. Use Value: Enables compliance with IEC 62368-1 fault response timing while eliminating discrete op-amp + comparator + logic components. |
Use Scenario: Phase current sensing and short-circuit protection in cordless power tools with 18–40 V battery inputs. IC Role / Device Role / Timing Role: High-bandwidth (105 kHz) amplification and comparator decision enable cycle-by-cycle current limiting during PWM commutation. Use Value: Prevents MOSFET destruction during stalled-rotor or cable-short events by triggering gate driver disable within 10 µs. |
| Cordless Power Tools | Headsets and Earbuds |
|
Use Scenario: Battery discharge current monitoring and pack-level overcurrent cutoff in lithium-ion powered drills and saws. IC Role / Device Role / Timing Role: Measures bidirectional current through low-side shunt; ALERT latched to halt charging/discharging upon fault. Use Value: Supports UL 2595 compliance with fast, repeatable trip thresholds independent of supply voltage variation. |
Use Scenario: In-ear speaker driver current limiting and thermal foldback in active noise cancellation earbuds. IC Role / Device Role / Timing Role: Low-offset (≤150 µV), low-power (350 µA) sensing enables accurate current measurement at µA-level standby and mA-level playback currents. Use Value: Extends battery runtime by enabling precise current-based state-of-charge estimation without adding measurable load. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar current-sense amplifier with comparator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| INA381A3IDGSR | Fixed gain of 100 V/V (vs. 200 V/V); otherwise identical pinout, specs, and functionality. | Better suited for higher shunt voltages (>20 mV) or systems requiring reduced gain headroom before ADC saturation. | Select when full-scale shunt voltage exceeds 10 mV - avoids clipping while maintaining same accuracy, speed, and footprint. |
| INA240A4DGNR | Higher bandwidth (350 kHz vs. 105 kHz), lower offset (±5 µV typ), but no integrated comparator; requires external logic for alert generation. | Preferred for ultra-high-precision, high-speed current loop control where comparator functionality is implemented separately. | Choose when system already includes FPGA/MCU GPIO for alert handling and demands sub-10 µV offset or >200 kHz bandwidth. |
Compared with INA381A4IDGSR, INA381A3IDGSR offers halved gain for wider dynamic range at higher shunt voltages, while INA240A4DGNR trades integrated fault logic for superior analog performance - making each optimal for distinct trade-offs between integration density, precision, and system-level control architecture.
Availability
INA381A4IDGSR is available at Aetrix Electronics and suitable for merchant DC/DC converters, BLDC motor drives, and cordless power tools requiring stable component supply, long-term lifecycle support, and traceable sourcing for industrial production.
Supply support for INA381A4IDGSR 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 specializing in analog and embedded processing technologies, with decades of expertise in precision signal chain and power management ICs.
The INA381 product line delivers integrated current-sense amplifiers with onboard comparators for fast, reliable overcurrent protection - engineered specifically for high-efficiency, high-reliability power conversion and motor control systems.
FAQ
What is the maximum common-mode voltage the INA381A4IDGSR can handle?
The INA381A4IDGSR supports a common-mode input voltage range of –0.2 V to +26 V on its IN+ and IN– pins. This rating holds even when the device supply (VS) is unpowered, enabling robust high-side sensing on 24 V bus rails without level-shifting circuitry. The specification is guaranteed across the full operating temperature range of –40°C to +125°C.
Does the INA381A4IDGSR require external components to operate as a complete overcurrent detector?
The INA381A4IDGSR requires only two external components for basic overcurrent detection: a 10-kΩ pull-up resistor on the ALERT pin and an external reference voltage source (e.g., REF3140 or resistive divider) on CMPREF. No external op-amps, comparators, or logic gates are needed - the integrated 200× amplifier and comparator with 50 mV hysteresis deliver full functionality in one WSON-8 package.
How does the RESET pin affect the behavior of the ALERT output on the INA381A4IDGSR?
The RESET pin on the INA381A4IDGSR selects the alert mode: when pulled high (≥1.4 V), ALERT operates in transparent mode (output follows input state in real time); when pulled low (≤0.4 V), ALERT enters latched mode (output remains asserted until RESET is pulsed low again). An internal 100 kΩ pull-down ensures latched mode defaults if RESET is left floating.
What is the total overcurrent response time of the INA381A4IDGSR, and what contributes to it?
The total overcurrent response time of the INA381A4IDGSR is less than 10 µs. This includes the amplifier's small-signal settling time (dominated by its 105 kHz bandwidth), propagation delay through the comparator (400 ns typical), and internal logic latency. The value represents end-to-end time from current exceeding threshold at the shunt to ALERT assertion - verified under standard test conditions per SBOS848B.
Can the INA381A4IDGSR be used for bidirectional current sensing?
No - the INA381A4IDGSR is optimized for unidirectional current sensing. Its input stage and comparator architecture assume positive differential voltage (VIN+ > VIN–) during overcurrent events. For bidirectional applications requiring sign detection and dual-threshold alerting, TI recommends the INA240 or INA229 families, which support true bipolar input ranges and separate high/low fault outputs.
INA381A4IDGSR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- Zero-Drift
- Package/Case:
- 10-TFSOP, 10-MSOP (0.118", 3.00mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Function:
- Current Sense
- Sensing Method:
- High/Low-Side
- Accuracy:
- ±1%
- Voltage - Input:
- 0V ~ 26V
- Current - Output:
- -
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 10-VSSOP
INA381A4IDGSR FAQ
1.How can I place an order for INA381A4IDGSR through Aetrix?
Please submit a Request for Quotation (RFQ) for INA381A4IDGSR 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 INA381A4IDGSR reliable?
The price and inventory of INA381A4IDGSR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for INA381A4IDGSR is usually 5 days.
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4.How is shipping managed for INA381A4IDGSR?
INA381A4IDGSR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your INA381A4IDGSR 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 INA381A4IDGSR?
For technical support, including INA381A4IDGSR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your INA381A4IDGSR requirements.
6.How does Aetrix verify that INA381A4IDGSR is sourced from the original manufacturer or authorized distributors?
All INA381A4IDGSR 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 INA381A4IDGSR meets industry standards.
7.What is the process for return or replacement of INA381A4IDGSR?
All INA381A4IDGSR units undergo pre-shipment inspection (PSI). If there is an issue with INA381A4IDGSR, 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 INA381A4IDGSR part is unused and in its original packaging.
Return procedure for INA381A4IDGSR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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