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Texas Instruments INA381A1IDSGR
- Part No.:
- INA381A1IDSGR
- Manufacturer:
- Texas Instruments
- Category:
- Current Regulation/Management
- Package:
- 8-WFDFN Exposed Pad
- Datasheet:
-
INA381A1IDSGR.pdf
- Description:
- IC CURRENT SENSE 1% 8WSON
- Quantity:
- Payment:
- Shipping:
Inventory:22,250
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Product details
Overview
INA381A1IDSGR from Texas Instruments is a 26-V, high-speed current-sense amplifier with integrated comparator, designed for overcurrent detection in high-side and low-side shunt configurations. It delivers 20 V/V gain, ±500 µV max offset at 12 V common-mode, 350 kHz bandwidth, and 400 ns comparator propagation delay. It operates from 2.7 V to 5.5 V supply and supports –0.2 V to +26 V input common-mode range - enabling use in merchant server PSUs and cordless power tools.
For engineers reviewing the INA381A1IDSGR datasheet, INA381A1IDSGR pinout, INA381A1IDSGR application, or INA381A1IDSGR equivalent, this device serves as a single-chip solution for precision current monitoring and fast overcurrent alerting in DC/DC converters, BLDC motor drives, and battery-powered systems requiring sub-10 µs total fault response time.
Technical Context
The INA381A1IDSGR implements a zero-drift amplifier topology with rail-to-rail output swing and an independent open-drain comparator with 50 mV hysteresis. Its input stage withstands –0.2 V to +26 V common-mode voltage regardless of 2.7–5.5 V supply, enabling direct high-side sensing on 24-V rails without level-shifting. The comparator monitors VOUT (amplified shunt voltage) against an externally set CMPREF threshold and asserts ALERT within <2 µs for large-signal events.
It supports transparent and latched alert modes via RESET pin control, and features 1 µV/°C offset drift and 20 ppm/°C gain error drift over –40°C to +125°C. Total system overcurrent protection response time is <10 µs - combining amplifier settling, comparator propagation, and output drive capability.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Gain | 20 V/V - fixed ratio for scaling shunt voltage to measurable output; enables 50-mV full-scale current sense with 1-mΩ shunt at 5-A load. |
| Common-mode input range | –0.2 V to +26 V - supports direct high-side sensing on 24-V bus without external level shifters or isolated supplies. |
| Offset voltage (max) | ±500 µV at VCM = 12 V - ensures <1% error at 50-mV sense voltage; allows accurate low-current detection down to ~25 mA with 2-mΩ shunt. |
| Bandwidth | 350 kHz - captures fast current transients in BLDC motor commutation or PSU fault events without phase lag. |
| Comparator propagation delay | 400 ns (typ) - enables sub-microsecond overcurrent flagging; critical for protecting MOSFETs in high-frequency switching stages. |
| Supply voltage | 2.7 V to 5.5 V - compatible with standard 3.3-V or 5-V microcontroller I/O domains and ADC reference rails. |
| Quiescent current | 350 µA (max) - minimizes standby power in battery-operated tools and headsets where continuous monitoring is required. |
Pinout & Package
INA381A1IDSGR is housed in an 8-pin WSON package (2.00 mm × 2.00 mm) with exposed thermal pad. This thermally enhanced, space-constrained package supports high-density PCB layouts in compact power modules and motor drivers.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| IN+ | Analog input (noninverting) | Connects to supply side of shunt resistor; accepts common-mode up to +26 V independent of VS. |
| IN– | Analog input (inverting) | Connects to load side of shunt; differential input measures mV-level voltage drop across RSENSE. |
| VOUT | Analog output | Amplified shunt voltage (G × VSENSE); rail-to-rail swing supports direct interface to 3.3-V ADCs. |
| ALERT | Digital output (open-drain) | Active-low fault flag; requires external pull-up; sinks ≥3 mA to signal overcurrent to MCU GPIO or latch circuit. |
| RESET | Digital input | Configures alert mode: logic high = transparent; logic low = latched; cleared only by RESET assertion. |
| CMPIN | Analog input (comparator) | Accepts VOUT or filtered version; comparator compares this against CMPREF to trigger ALERT. |
| CMPREF | Analog input (reference) | Set by resistor divider or precision reference (e.g., REF3140); defines overcurrent threshold voltage. |
| GND | Ground | Device ground and thermal pad connection point; must be tied to system ground for thermal and noise performance. |
| VS+ | Power supply | 2.7–5.5 V single supply; powers both amplifier and comparator; decoupling capacitor required near pin. |
Key Features
| Feature | Design Value |
|---|---|
| Zero-drift amplifier architecture | Enables ±150 µV max offset at 0 V common-mode and 1 µV/°C drift - critical for stable baseline in temperature-varying environments like motor drives. |
| Integrated comparator with hysteresis | 50 mV built-in hysteresis prevents false triggering near threshold; eliminates need for external Schmitt-trigger components. |
| High-speed alert response | Total system overcurrent response <10 µs - combines amplifier bandwidth, comparator propagation, and output drive for real-time fault containment. |
| Wide common-mode tolerance | Operates with inputs at –0.2 V to +26 V while powered from 2.7–5.5 V - removes isolation requirements in 24-V industrial and automotive auxiliary systems. |
| Latched vs transparent alert modes | RESET pin selects behavior: latched mode holds ALERT until reset, enabling fault capture in interrupt-driven firmware; transparent mode mirrors instantaneous condition. |
Applications
| Merchant Server PSU | DC-Input BLDC Motor Drive |
|---|---|
|
Use Scenario: Real-time phase current monitoring and overcurrent shutdown in 48-V input server power supplies with digital PMBus control. IC Role / Device Role / Timing Role: Current-sense amplifier and comparator jointly provide <10 µs fault detection latency to protect synchronous rectifiers and prevent thermal runaway. Use Value: Eliminates separate op-amp + comparator + reference ICs; reduces BOM count by 3 devices and saves >3 mm² PCB area in tight 1U form factors. |
Use Scenario: High-bandwidth current feedback for field-oriented control (FOC) and instantaneous overcurrent protection during motor stall in cordless drills. IC Role / Device Role / Timing Role: Amplifies shunt voltage with 350 kHz bandwidth and triggers latched ALERT within 2 µs to disable gate drivers before MOSFET SOA violation. Use Value: Enables use of lower-value shunts (e.g., 1 mΩ), reducing power loss by >40% versus 5-mΩ alternatives while maintaining ±1% full-scale accuracy. |
| Cordless Power Tool Battery Pack | Headset/Earbud Charging Circuit |
|
Use Scenario: Bidirectional current monitoring and short-circuit detection in 21-V Li-ion battery packs with integrated fuel gauging. IC Role / Device Role / Timing Role: Measures charge/discharge current via low-side shunt; ALERT flags reverse-current faults or cell imbalance events. Use Value: Supports ±0.2 V common-mode - tolerates negative transients during hot-plug events without latch-up or damage. |
Use Scenario: Input current limiting and overcurrent cutoff in USB-C PD charging circuits for true wireless stereo earbuds. IC Role / Device Role / Timing Role: Monitors 5-V input current with 20 V/V gain; comparator alerts MCU when >2 A is drawn, triggering dynamic load shedding. Use Value: 350 µA quiescent current extends shelf life; WSON-8 package fits under compact battery cells with minimal thermal footprint. |
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 |
|---|---|---|---|
| INA240A1DRCR | 20 V/V gain, 80 kHz bandwidth, 1.5 µs alert response; no RESET-controlled latching; higher offset (±100 µV typ). | Better suited for lower-speed, cost-sensitive industrial sensors; lacks fast transient response needed for motor drive protection. | Select INA240A1DRCR only if bandwidth <100 kHz suffices and latched alert mode is unnecessary. |
| MAX40056ATA+T | 20 V/V gain, 400 kHz bandwidth, 350 ns comparator delay; requires external reference; no integrated hysteresis. | Requires external 50-mV hysteresis network and reference IC; increases layout complexity and component count. | Choose MAX40056ATA+T only when design already uses MAXIM's reference ecosystem and board space permits extra passives. |
Compared with INA240A1DRCR and MAX40056ATA+T, the INA381A1IDSGR uniquely integrates latched/transparent alert control, 50-mV hysteresis, and <10 µs total fault response in a single WSON-8 package - simplifying safety-critical overcurrent protection without sacrificing speed or accuracy.
Availability
INA381A1IDSGR is available at Aetrix Electronics and suitable for merchant server PSUs, DC-input BLDC motor drives, and cordless power tool battery management systems requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.
Supply support for INA381A1IDSGR 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 amplifiers and power management ICs.
The INA381 product line targets high-reliability current sensing in power conversion and motor control, delivering integrated analog + digital fault detection to reduce system-level design complexity and improve functional safety margins.
FAQ
What is the maximum common-mode voltage the INA381A1IDSGR can handle?
The INA381A1IDSGR supports a common-mode input voltage range of –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 bus rails without external level-shifting circuitry. The device remains functional and undamaged even when VS is removed while 26 V is present on IN+ and IN–.
Does the INA381A1IDSGR require an external reference for the comparator?
No - the INA381A1IDSGR does not include an internal reference, but CMPREF accepts any externally generated reference voltage (e.g., from REF3140 or resistor divider). The comparator compares CMPIN (typically VOUT) against this user-defined voltage to determine overcurrent thresholds; no internal reference is used or required.
How does the RESET pin affect alert behavior in the INA381A1IDSGR?
The RESET pin configures the alert mode: logic high enables transparent mode (ALERT follows instantaneous comparator output), while logic low enables latched mode (ALERT stays asserted until RESET is pulsed high). This dual-mode flexibility supports both real-time monitoring and fault capture in interrupt-driven firmware without additional logic gates.
What is the total overcurrent response time of the INA381A1IDSGR?
The total system overcurrent response time of the INA381A1IDSGR is less than 10 µs. This includes amplifier output settling, comparator propagation delay (400 ns typ), and open-drain output drive - verified under conditions of 1-mV input overdrive and 10-kΩ pull-up. This enables reliable protection of fast-switching power stages.
Can the INA381A1IDSGR be used for bidirectional current sensing?
Yes - the INA381A1IDSGR supports bidirectional sensing when the shunt is placed in a low-side configuration with GND-referenced load. Its –0.2 V common-mode minimum allows detection of reverse current flow (e.g., battery discharge vs. charge), provided the comparator reference is configured to detect both polarities using external circuitry such as a level-shifting op-amp.
INA381A1IDSGR 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)
INA381A1IDSGR FAQ
1.How can I place an order for INA381A1IDSGR through Aetrix?
Please submit a Request for Quotation (RFQ) for INA381A1IDSGR 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 INA381A1IDSGR reliable?
The price and inventory of INA381A1IDSGR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for INA381A1IDSGR is usually 5 days.
3.What payment methods are accepted for INA381A1IDSGR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for INA381A1IDSGR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for INA381A1IDSGR?
INA381A1IDSGR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your INA381A1IDSGR 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 INA381A1IDSGR?
For technical support, including INA381A1IDSGR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your INA381A1IDSGR requirements.
6.How does Aetrix verify that INA381A1IDSGR is sourced from the original manufacturer or authorized distributors?
All INA381A1IDSGR 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 INA381A1IDSGR meets industry standards.
7.What is the process for return or replacement of INA381A1IDSGR?
All INA381A1IDSGR units undergo pre-shipment inspection (PSI). If there is an issue with INA381A1IDSGR, 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 INA381A1IDSGR part is unused and in its original packaging.
Return procedure for INA381A1IDSGR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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