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Texas Instruments INA381A3IDSGR
- Part No.:
- INA381A3IDSGR
- Manufacturer:
- Texas Instruments
- Category:
- Current Regulation/Management
- Package:
- 8-WFDFN Exposed Pad
- Datasheet:
-
INA381A3IDSGR.pdf
- Description:
- IC CURRENT SENSE 1% 8WSON
- Quantity:
- Payment:
- Shipping:
Inventory:6,477
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Product details
Overview
INA381A3IDSGR from Texas Instruments is a 26-V, high-speed current-sense amplifier with integrated comparator and fixed gain of 100 V/V, designed for overcurrent detection in high-side and low-side shunt monitoring. It operates from 2.7 V to 5.5 V, supports –0.2 V to +26 V common-mode input, delivers <150 µV max offset at 0 V CM, and achieves <10 µs total system overcurrent response time in DC/DC power supplies and motor drives.
For engineers reviewing the INA381A3IDSGR datasheet, INA381A3IDSGR pinout, INA381A3IDSGR application, or INA381A3IDSGR equivalent, this page provides verified functional context, validated WSON-8 package mapping, confirmed comparator hysteresis (50 mV), real-world alert propagation timing (<2 µs comparator-only), and precise gain-specific bandwidth (150 kHz) - all directly extracted from TI's SBOS848B production datasheet.
Technical Context
The INA381A3IDSGR implements a zero-drift topology enabling 150 µV max input offset at 0 V common-mode and 1 µV/°C drift over –40°C to +125°C. Its amplifier stage provides 100 V/V fixed gain with 1% max gain error at 25°C and 20 ppm/°C gain error drift.
The integrated open-drain comparator features 50 mV hysteresis, 400 ns typical propagation delay, transparent/latched alert modes controlled by RESET, and threshold setting via external voltage on CMPREF - independent of the amplifier output path.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Gain | 100 V/V - sets fixed scaling from shunt voltage to VOUT; enables 10-mV full-scale sensing with 1-V output swing. |
| Common-mode range | –0.2 V to +26 V - supports direct high-side sensing on 24-V bus rails without level-shifting or auxiliary supplies. |
| Offset voltage (max) | 150 µV at VCM = 0 V - allows accurate low-current measurement with ≤10-mΩ shunts in battery-powered tools. |
| Bandwidth | 150 kHz - captures fast transients in BLDC motor phase currents and PSU fault events without signal attenuation. |
| Comparator hysteresis | 50 mV - prevents false triggering near threshold in noisy environments such as cordless tool motor commutation. |
| Total overcurrent response | <10 µs - combines amplifier settling and comparator propagation to enable sub-cycle protection in 50-kHz+ switching converters. |
| Supply voltage | 2.7 V to 5.5 V - compatible with standard microcontroller I/O rails and enables single-supply operation in space-constrained modules. |
Pinout & Package
INA381A3IDSGR is packaged in an 8-pin WSON (DSG) with 2.00 mm × 2.00 mm body size and exposed thermal pad. The thermal pad must be externally connected to system ground for thermal and electrical performance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| IN+ | Analog input | Connects to supply side of shunt resistor; accepts up to +26 V common-mode regardless of VS. |
| IN– | Analog input | Connects to load side of shunt resistor; differential pair with IN+ defines sensed current polarity. |
| VOUT | Analog output | Amplified shunt voltage (100×); rail-to-rail swing supports direct ADC interfacing with 3.3-V or 5-V microcontrollers. |
| ALERT | Digital output | Active-low open-drain flag; requires external pullup; asserts within <2 µs of overthreshold condition. |
| RESET | Digital input | Selects latched (pulled low) or transparent (pulled high) alert mode; no internal pullup. |
| CMPIN | Analog input | Comparator input node; typically tied to VOUT for direct threshold comparison. |
| CMPREF | Analog input | Comparator reference voltage; sets overcurrent threshold via external divider or precision reference (e.g., REF3140). |
| GND | Ground | Device ground reference; thermal pad must be soldered to PCB ground plane for thermal dissipation and noise immunity. |
Key Features
| Feature | Design Value |
|---|---|
| Zero-drift architecture | Enables stable 150 µV max offset at 0 V CM and 1 µV/°C drift - critical for temperature-invariant current measurement in automotive and industrial environments. |
| Integrated comparator with hysteresis | 50 mV hysteresis eliminates chatter during threshold crossing; 400 ns propagation ensures rapid fault signaling without external logic. |
| High common-mode tolerance | Operates with –0.2 V to +26 V inputs while powered from 2.7–5.5 V - eliminates need for isolated supplies or level shifters in 24-V systems. |
| Low quiescent current | 350 µA max IQ - supports always-on monitoring in battery-backed applications like UPS and portable medical devices. |
| WSON-8 thermal design | Exposed thermal pad and 43.4°C/W RθJB enable >1-W dissipation in compact layouts - suitable for high-density server PSU modules. |
Applications
| Merchant DC/DC Power Supply | DC-Input BLDC Motor Drive |
|---|---|
Use Scenario: Real-time output current monitoring and overcurrent shutdown in 48-V telecom rectifiers and server VRMs. IC Role / Device Role / Timing Role: Current-sense amplifier and comparator jointly provide sub-10-µs fault detection and latchable alert for PMBus-controlled shutdown. Use Value: Enables compliance with IEC 62368-1 fault response requirements while eliminating discrete comparator and reference components. |
Use Scenario: Phase current sensing and short-circuit protection in cordless power tools with 18–40-V battery packs. IC Role / Device Role / Timing Role: High-bandwidth (150 kHz) amplification and comparator-triggered brake activation upon stall detection. Use Value: Reduces BOM count by integrating precision gain, comparator, and hysteresis - critical for cost-sensitive consumer motor control. |
| Cordless Power Tool Battery Pack | Headset/Earbud Charging Case |
Use Scenario: In-line charge/discharge current monitoring and cell-balancing enablement in multi-cell Li-ion packs. IC Role / Device Role / Timing Role: Low-offset (150 µV) sensing enables accurate 50-mA–5-A dynamic range measurement across temperature. Use Value: Supports ±1% current accuracy over –20°C to +70°C without calibration - extends runtime estimation fidelity. |
Use Scenario: Input current limiting and overcurrent cutoff during USB-C PD charging of compact audio accessories. IC Role / Device Role / Timing Role: Fast-alert comparator (400 ns) triggers MCU-controlled MOSFET gate shutdown before thermal damage occurs. Use Value: Fits in 2.0 mm × 2.0 mm footprint - essential for ultra-thin charging case PCBs where space is constrained to <10 mm². |
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 |
|---|---|---|---|
| INA240A3D | Same 100 V/V gain, but wider –4 V to +80 V common-mode range; higher 2.5 µV/°C offset drift; no integrated comparator. | Requires external comparator and reference for overcurrent flag generation - increases layout area and component count. | Choose INA240A3D only when >26 V common-mode (e.g., 48-V industrial drives) is required and comparator integration is unnecessary. |
| MAX40056ATA+T | 100 V/V gain, 2.8 V to 5.5 V supply, 250 kHz bandwidth, but no comparator; 350 µV max offset at 25°C. | Lacks integrated alert functionality - mandates external GPIO monitoring and firmware-based thresholding, increasing MCU overhead. | Prefer MAX40056ATA+T when analog output fidelity is prioritized over autonomous fault response and system-level latency is managed in software. |
Compared with INA381A3IDSGR, INA240A3D trades comparator integration for extended common-mode range, while MAX40056ATA+T sacrifices autonomous protection for marginally higher bandwidth and lower supply sensitivity - making INA381A3IDSGR optimal for space- and latency-constrained embedded overcurrent systems.
Availability
INA381A3IDSGR is available at Aetrix Electronics and suitable for merchant network/server PSU, DC-input BLDC motor drive, and cordless power tool applications requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.
Supply support for INA381A3IDSGR 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 company specializing in analog and embedded processing technologies, with leadership in precision analog signal chain solutions.
The INA381 product line targets high-speed, integrated current-sensing for power conversion and motor control - delivering combined amplifier + comparator functionality in miniature WSON and VSSOP packages for space-constrained, safety-critical systems.
FAQ
What is the maximum common-mode voltage supported by the INA381A3IDSGR?
The INA381A3IDSGR supports a common-mode input voltage range of –0.2 V to +26 V, independent of its 2.7 V to 5.5 V supply voltage. This allows direct high-side sensing on 24-V bus rails without auxiliary level-shifting circuitry. The device remains functional and undamaged even when the 26-V common-mode is applied with VS = 0 V, per absolute maximum ratings in SBOS848B.
Does the INA381A3IDSGR require external components to operate as a complete overcurrent detector?
The INA381A3IDSGR requires only two external components for basic overcurrent detection: a 10-kΩ pullup resistor on the ALERT pin and a voltage source (e.g., resistive divider or REF3140) on CMPREF to set the threshold. No external op-amps, comparators, or references are needed - the amplifier, comparator, hysteresis, and latch/transparent mode control are fully integrated within the INA381A3IDSGR die.
What is the bandwidth and slew rate of the INA381A3IDSGR amplifier stage?
The INA381A3IDSGR amplifier stage has a small-signal bandwidth of 150 kHz and a large-signal slew rate of 2 V/µs. These values are gain-dependent and specified for the A3 variant (100 V/V) in Section 6.5 of SBOS848B. The 150 kHz bandwidth enables accurate capture of fast current transients in 50-kHz+ switching converters and BLDC motor commutation events.
How does the RESET pin configure alert behavior in the INA381A3IDSGR?
The RESET pin on the INA381A3IDSGR selects between transparent and latched alert modes: when RESET is pulled high (≥1.4 V), ALERT follows the comparator output state in real time; when RESET is pulled low (≤0.4 V), ALERT remains asserted until RESET is toggled high again. This latching behavior enables reliable fault capture in systems where the overcurrent event may be brief relative to MCU polling intervals.
Is the INA381A3IDSGR pin-compatible with other variants in the INA381 family?
The INA381A3IDSGR shares identical pinout and package (WSON-8 DSG) with INA381A1IDSGR, INA381A2IDSGR, and INA381A4IDSGR - all variants use the same DSG footprint and terminal assignments. Gain selection is internal and fixed per part number; no external resistor networks or configuration pins are required to change gain, simplifying board reuse across current-sense ranges.
INA381A3IDSGR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- Zero-Drift
- Package/Case:
- 8-WFDFN Exposed Pad
- 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:
- 8-WSON (2x2)
INA381A3IDSGR FAQ
1.How can I place an order for INA381A3IDSGR through Aetrix?
Please submit a Request for Quotation (RFQ) for INA381A3IDSGR 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 INA381A3IDSGR reliable?
The price and inventory of INA381A3IDSGR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for INA381A3IDSGR is usually 5 days.
3.What payment methods are accepted for INA381A3IDSGR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for INA381A3IDSGR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for INA381A3IDSGR?
INA381A3IDSGR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your INA381A3IDSGR 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 INA381A3IDSGR?
For technical support, including INA381A3IDSGR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your INA381A3IDSGR requirements.
6.How does Aetrix verify that INA381A3IDSGR is sourced from the original manufacturer or authorized distributors?
All INA381A3IDSGR 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 INA381A3IDSGR meets industry standards.
7.What is the process for return or replacement of INA381A3IDSGR?
All INA381A3IDSGR units undergo pre-shipment inspection (PSI). If there is an issue with INA381A3IDSGR, 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 INA381A3IDSGR part is unused and in its original packaging.
Return procedure for INA381A3IDSGR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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