My Inquiry
My Account
Allegro MicroSystems A1391SEHLX-T
- Part No.:
- A1391SEHLX-T
- Manufacturer:
- Allegro MicroSystems
- Category:
- Linear, Compass (ICs)
- Package:
- 6-PowerWFDFN
- Datasheet:
-
A1391SEHLX-T.pdf
- Description:
- SENSOR HALL ANALOG 6MLP/DFN
- Quantity:
- Payment:
- Shipping:
Inventory:1,502
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
A1391SEHLX-T from Allegro MicroSystems is a micropower 3 V linear Hall-effect sensor IC with tri-state output and user-selectable sleep mode, designed for precise magnetic field sensing in battery-constrained systems. It delivers 1.25 mV/G typical sensitivity, 50% ratiometric quiescent output voltage referenced to VREF, and operates from 2.5–3.5 V supply. Its <25 µA sleep current and high-impedance output enable multi-sensor sharing of a single ADC input in portable tools and digital cameras.
For engineers reviewing the A1391SEHLX-T datasheet, A1391SEHLX-T pinout, A1391SEHLX-T application, or A1391SEHLX-T equivalent, key selection considerations include its ratiometric VREF-referenced output scaling, 10 kHz bandwidth, 6-pin MLP/DFN package footprint, and microprocessor-controllable sleep timing (tPON = 60 µs max, tPOFF = 1 µs).
Technical Context
The A1391SEHLX-T integrates a Hall element, dynamic offset cancellation circuitry, chopper-stabilized amplifier, and temperature-compensated gain/offset trimming. Its output voltage is ratiometric to the externally supplied VREF voltage-not to VCC-enabling stable performance across supply variations when VREF is derived from a precision source.
Sleep mode is controlled via logic-level signal on Pin 5 (SLEEP), with active-high threshold at 0.45×VCC and sleep-low threshold at 0.20×VCC. During sleep, OUT enters high-impedance state (ROUT ≈ 4 MΩ), allowing multiple A1391SEHLX-T devices to share one ADC input without contention.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Sensitivity | 1.25 mV/G (typical at TA = 25°C, VCC = VREF = 3.0 V); enables accurate low-field detection in proximity and position sensing. |
| Supply Voltage Range | 2.5–3.5 V; compatible with standard Li-ion and coin-cell battery rails without regulation. |
| Sleep Current | <25 µA (typical at TA = 25°C); extends battery life in intermittently active sensing applications. |
| Active Supply Current | 3.2 mA (typical at TA = 25°C); supports continuous operation while maintaining micropower profile. |
| Output Bandwidth | 10 kHz (–3 dB point); sufficient for motion, speed, and position feedback in handheld and portable equipment. |
| Quiescent Output Voltage | 0.500 × VREF (typical at B = 0 G); ratiometric reference ensures consistent zero-point across VREF variations. |
| Power-On Time | 60 µs max (time from SLEEP HIGH to 90% valid output); enables rapid wake-up for event-triggered sampling. |
Pinout & Package
Package: 6-pin MLP/DFN (2.0 × 3.0 mm, 0.75 mm nominal height), Pb-free with 100% matte tin leadframe plating. Exposed thermal pad improves PCB heat dissipation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - VCC | Primary power supply input | Accepts 2.5–3.5 V; internal regulator powers core circuitry; zener clamped at 8.3 V. |
| 2 - OUT | Analog voltage output | Tri-state: active-mode low-impedance (20 Ω), sleep-mode high-impedance (~4 MΩ); connects directly to ADC inputs. |
| 3 - GND | Ground reference | Primary ground return path for VCC and internal analog/digital blocks. |
| 4 - GND | Secondary ground terminal | Reduces ground loop impedance and improves noise immunity in high-density layouts. |
| 5 - SLEEP | Mode control input | Logic HIGH (≥0.45×VCC) enables active mode; LOW (≤0.20×VCC) forces sleep; input current ≤1 µA. |
| 6 - VREF | Ratiometric reference supply | Defines output scaling: quiescent voltage = 0.5×VREF, sensitivity ∝ VREF; must be ≤ VCC and ≥2.5 V. |
Key Features
| Feature | Design Value |
|---|---|
| Ratiometric output referenced to VREF | Ensures consistent sensitivity and zero-point even if VCC varies, as long as VREF remains stable-critical for battery-powered systems with aging or load-dependent supply rails. |
| User-selectable sleep mode | Reduces current draw from 3.2 mA to <25 µA via external logic control, enabling duty-cycled operation without firmware overhead or external switches. |
| High-impedance tri-state output | Allows up to N A1391SEHLX-T sensors to share one ADC input line, reducing system component count and PCB area in multi-axis or multi-zone sensing designs. |
| Dynamic offset cancellation | Eliminates 1/f noise and thermal drift using chopper stabilization at 200 kHz, delivering stable DC-coupled output without external filtering. |
| Temperature-stable quiescent voltage | ΔVOUTQ variation ≤ ±1% over –20°C to +85°C ambient, ensuring reliable zero-crossing detection across operating environments. |
Applications
| Smartphone Flip Detection | Digital Camera Lens Position Sensing |
|---|---|
|
Use Scenario: Detect clamshell lid open/close state in smartphones using a magnet embedded in the lid and A1391SEHLX-T mounted on the main board. IC Role / Device Role / Timing Role: Linear Hall sensor providing analog voltage proportional to magnetic field strength; output sampled by host MCU's ADC during periodic wake cycles. Use Value: Sleep current <25 µA minimizes standby drain; ratiometric VREF referencing maintains accuracy despite battery voltage sag during RF transmission. |
Use Scenario: Monitor lens barrel extension/retraction in compact digital cameras by tracking magnet position along optical axis. IC Role / Device Role / Timing Role: Precision linear position transducer; output scaled to lens displacement via calibrated VREF; sampled only during autofocus sequence. Use Value: 1.25 mV/G sensitivity resolves sub-millimeter lens movement; 10 kHz bandwidth captures fast actuator motion without aliasing. |
| Portable Power Tool RPM Monitoring | Wearable Fitness Tracker Motion Capture |
|
Use Scenario: Measure motor rotation speed in cordless drills via gear tooth passing near A1391SEHLX-T mounted adjacent to motor housing. IC Role / Device Role / Timing Role: Magnetic field zero-crossing detector feeding pulse train to MCU timer input; active only during tool operation. Use Value: High-impedance sleep mode prevents loading of shared ADC bus; chopper stabilization rejects EMI from motor commutation noise. |
Use Scenario: Sense wrist rotation and arm swing orientation in fitness bands using dual-axis magnet placement and A1391SEHLX-T on flex PCB. IC Role / Device Role / Timing Role: Low-power magnetic field transducer; synchronized wake-up triggered by accelerometer interrupt to capture motion snapshots. Use Value: 2.0 × 3.0 mm DFN footprint fits constrained wearable space; 0.75 mm height avoids interference with battery or display stackup. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar linear Hall-effect sensor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AL33030EUST-13 | Higher sensitivity (5 mV/G), no sleep mode, 3.3 V fixed supply only, SOT-23-3 package | Lacks power-gating capability; requires always-on supply; unsuitable for battery lifetime optimization | Select when higher resolution is needed and continuous operation is acceptable. |
| TLE493DW2B6A0HTSA1 | I²C digital output, 3-axis sensing, 2.8–3.5 V supply, TSSOP-16 package, integrated ADC and digital interface | Replaces analog signal chain with digital communication; adds processing overhead but eliminates external ADC requirement | Select when system already uses I²C infrastructure and multi-axis data fusion is required. |
Compared with AL33030EUST-13 and TLE493DW2B6A0HTSA1, the A1391SEHLX-T uniquely balances ultra-low sleep current, analog ratiometric output, and minimal footprint-making it optimal for cost-sensitive, single-axis, battery-operated analog-sensing nodes where ADC resources are shared.
Availability
A1391SEHLX-T is available at Aetrix Electronics and suitable for portable medical monitors, smart home sensors, and industrial handheld testers requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.
Supply support for A1391SEHLX-T 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
Allegro MicroSystems is a U.S.-based semiconductor company specializing in high-performance magnetic sensing and power ICs, with design centers in North America, Europe, and Asia.
The A139x family was developed specifically for micropower, ratiometric linear Hall sensing in consumer and industrial portable electronics-emphasizing sleep-mode efficiency, output stability, and ease of integration into resource-constrained systems.
FAQ
What is the function of the VREF pin on the A1391SEHLX-T?
The VREF pin on the A1391SEHLX-T sets the ratiometric reference for both quiescent output voltage (VOUTQ = 0.500 × VREF) and sensitivity (Sens ∝ VREF). Unlike VCC, which powers internal circuitry, VREF defines the analog scaling baseline-so output accuracy depends on VREF stability, not VCC. VREF must be between 2.5 V and VCC; applying less than 2.5 V degrades accuracy.
Can the A1391SEHLX-T operate without an external bypass capacitor?
No-the A1391SEHLX-T requires an external 0.1 µF ceramic bypass capacitor placed close between VCC and GND. This capacitor suppresses noise from both external sources and the internal 200 kHz chopper-stabilization circuitry. Omitting it increases output noise (e.g., up to 20 mVpp for A1391) and risks instability, especially in noisy environments like motor-driven tools or RF-rich mobile devices.
How does the A1391SEHLX-T handle multiple devices sharing one ADC input?
The A1391SEHLX-T supports multi-device ADC sharing via its tri-state output: only one device is held in active mode (SLEEP = HIGH) while others remain in sleep mode (SLEEP = LOW), placing their outputs in high-impedance state (~4 MΩ). This prevents signal contention. Timing must ensure no two devices exit sleep simultaneously-microprocessor GPIO sequencing is recommended to avoid >0.1 V output overvoltage conditions.
Is the A1391SEHLX-T suitable for automotive applications?
No-Allegro explicitly states that A139x devices sold in DFN packages (including A1391SEHLX-T) are not intended for automotive applications. They lack AEC-Q100 qualification, extended temperature range beyond –20°C to +85°C, and automotive-grade reliability testing. For automotive use, consider Allegro's A132x or A133x families, which offer qualified variants in SOIC or TSSOP packages.
What is the maximum allowable voltage on the SLEEP pin of the A1391SEHLX-T?
The SLEEP pin of the A1391SEHLX-T accepts logic signals up to VCC + 0.5 V (absolute maximum), per electrical characteristics. However, for robust operation with VCC = 3.0 V, the recommended high-level input is 0.45 × VCC = 1.35 V minimum, and low-level is 0.20 × VCC = 0.6 V maximum. Exceeding VCC + 0.5 V risks latch-up or permanent damage, especially during power sequencing mismatches.
A1391SEHLX-T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Allegro MicroSystems
- Series:
- A139x
- Package/Case:
- 6-PowerWFDFN
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Technology:
- Hall Effect
- Axis:
- Single
- Output Type:
- Analog Voltage
- Sensing Range:
- -
- Voltage - Supply:
- 2.5V ~ 3.5V
- Current - Supply (Max):
- 3.2mA
- Current - Output (Max):
- -
- Resolution:
- -
- Bandwidth:
- 10kHz
- Operating Temperature:
- -20°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Features:
- Sleep Mode, Temperature Compensated
- Supplier Device Package:
- 6-MLP/DFN (2x3)
- Mounting Type:
- Surface Mount
A1391SEHLX-T FAQ
1.How can I place an order for A1391SEHLX-T through Aetrix?
Please submit a Request for Quotation (RFQ) for A1391SEHLX-T 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 A1391SEHLX-T reliable?
The price and inventory of A1391SEHLX-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for A1391SEHLX-T is usually 5 days.
3.What payment methods are accepted for A1391SEHLX-T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for A1391SEHLX-T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for A1391SEHLX-T?
A1391SEHLX-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your A1391SEHLX-T 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 A1391SEHLX-T?
For technical support, including A1391SEHLX-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your A1391SEHLX-T requirements.
6.How does Aetrix verify that A1391SEHLX-T is sourced from the original manufacturer or authorized distributors?
All A1391SEHLX-T 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 A1391SEHLX-T meets industry standards.
7.What is the process for return or replacement of A1391SEHLX-T?
All A1391SEHLX-T units undergo pre-shipment inspection (PSI). If there is an issue with A1391SEHLX-T, 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 A1391SEHLX-T part is unused and in its original packaging.
Return procedure for A1391SEHLX-T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
A1391SEHLX-T Tags
-
DRV5053VAQDBZR
Texas Instruments
-
MMC5603NJ
Memsic Inc.
-
DRV5055A1QDBZR
Texas Instruments
-
MLX90392ELQ-AAA-011-RE
Melexis Technologies NV
-
CT100LW-HS6
Allegro MicroSystems
-
DRV5056A1ELPGMQ1
Texas Instruments
-
A1304ELHLX-T
Allegro MicroSystems
-
MMC5633NJL
Memsic Inc.
-
A1308KUA-2-T
Allegro MicroSystems
-
A1308KUA-1-T
Allegro MicroSystems
-
SI7210-B-04-IVR
Silicon Labs
-
A1308LLHLT-2-T
Allegro MicroSystems
Tech Hub
A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
