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Diodes Incorporated AH1921-W-7
- Part No.:
- AH1921-W-7
- Manufacturer:
- Diodes Incorporated
- Category:
- Switches (Solid State)
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
AH1921-W-7.pdf
- Description:
- MAGNETIC SWITCH OMNIPOL SC59-3
- Quantity:
- Payment:
- Shipping:
Inventory:15,435
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Product details
Overview
AH1921-W-7 from Diodes Incorporated is an ultra-low power digital omnipolar Hall-effect switch IC with open-drain output, operating from 1.6V to 5.5V supply, consuming only 1.6μA average current at 3V, and rated for -40°C to +85°C operation - deployed in battery-powered utility meters, smoke detectors, and IoT end-nodes requiring magnetic proximity sensing.
For engineers reviewing the AH1921-W-7 datasheet, AH1921-W-7 pinout, AH1921-W-7 application, or AH1921-W-7 equivalent, key selection criteria include its 60G typical operate point (BOP), 45G typical release point (BRP), 15G hysteresis, 0.1V output on-voltage at 0.1mA, and SC59 package compatibility with space-constrained PCB layouts.
Technical Context
The AH1921-W-7 implements a chopper-stabilized Hall sensor architecture with sleep/awake logic that cycles internal sampling every 30–80ms, reducing average current while maintaining magnetic threshold stability across temperature and supply voltage variations. Its hibernating clocking system enables deterministic wake-up latency of 30–80μs after magnetic field change detection.
As an omnipolar switch, it activates with either North or South pole orientation perpendicular to the non-marking side of the SC59 package, with magnetic operate points ranging from ±30G to ±90G and release points from ±22G to ±67G - ensuring reliable switching under mechanical stress and thermal drift.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage | 1.6V to 5.5V - supports single-cell Li-ion, alkaline, or low-VDD microcontrollers without level-shifting. |
| Average Supply Current | 1.6μA at 3V - enables >10-year battery life in 10-year metering applications with 10-second sampling intervals. |
| Magnetic Operate Point (BOP) | ±30G to ±90G - accommodates magnet strength variation and air-gap tolerance in consumer and industrial enclosures. |
| Hysteresis (BHY) | 15G minimum - prevents chatter during slow-field transitions near threshold, critical for cover-detect reliability. |
| Output Type | Open-drain - allows wired-OR configuration, pull-up flexibility, and interface with 1.8V/3.3V/5V logic domains. |
| ESD Rating | 6kV HBM - eliminates need for external TVS in handheld and exposed-sensor designs. |
| Operating Temperature | -40°C to +85°C - qualified for outdoor utility metering and residential smoke alarm environments. |
Pinout & Package
Package: SC59 - surface-mount, 3-pin, low-profile (0.35–0.50mm height), lead-free, RoHS-compliant package with Hall sensor die centered beneath pin 1 marking area.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 VDD | Power supply input | Accepts 1.6V–5.5V; requires 100nF decoupling capacitor placed adjacent to minimize noise-induced false triggers. |
| 2 OUTPUT | Open-drain output | Sinks up to 1mA; must be externally pulled up; asserts low when B > |BOP|, releases high when B < |BRP|. |
| 3 GND | Ground reference | Return path for Hall plate, amplifier, and output driver; connects to PCB ground plane for ESD and thermal performance. |
Key Features
| Feature | Design Value |
|---|---|
| Omnipolar magnetic sensitivity | Detects either North or South pole without polarity alignment - simplifies mechanical assembly in smart covers and docking systems. |
| Chopper-stabilized architecture | Reduces offset drift to <±0.5G/°C - maintains consistent BOP/BRP over full temperature range without calibration. |
| Hibernating clocking system | Enables 1.6μA average current - extends CR2032 battery life beyond 10 years in intermittent-sampling IoT nodes. |
| SC59 package footprint | Compatible with standard SOT-23 pick-and-place equipment and reflow profiles - no process change required for high-volume manufacturing. |
| 6kV HBM ESD rating | Withstands handling and field surges without external protection - reduces BOM count and PCB area in smoke detector modules. |
Applications
| Smart Cover Detection | Utility Meter Tamper Sensing |
|---|---|
Use Scenario: Detect lid closure on tablet PC or clamshell phone using embedded magnet and PCB-mounted AH1921-W-7. IC Role / Device Role / Timing Role: Digital proximity switch providing logic-level state transition on magnet approach/retraction. Use Value: Eliminates mechanical switches prone to wear; enables zero-power standby via ultra-low IDD(AVG) during closed-lid state. | Use Scenario: Monitor unauthorized meter enclosure opening in gas/water meters powered by primary lithium batteries. IC Role / Device Role / Timing Role: Tamper-alert sensor triggering MCU wake-up and secure logging upon magnetic field disruption. Use Value: 1.6μA average current ensures >15-year battery life while maintaining tamper responsiveness per ANSI C12.22. |
| IoT End-Node Position Sensing | Smoke Detector Door Interlock |
Use Scenario: Sense actuator position in battery-powered smart lock or HVAC damper control node. IC Role / Device Role / Timing Role: Magnetic position indicator interfacing directly with ultra-low-power MCU GPIO. Use Value: Open-drain output allows direct connection to 1.8V MCU inputs; hysteresis prevents false reporting during vibration. | Use Scenario: Confirm smoke detector front cover is fully seated before enabling alarm self-test sequence. IC Role / Device Role / Timing Role: Safety-critical interlock switch verifying mechanical integrity prior to functional validation. Use Value: 6kV ESD rating withstands ESD events during field servicing; -40°C to +85°C range covers garage and attic installations. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar omnipolar Hall-effect switch applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ALLEGRO A3212LLHLT-T | Higher average current (5μA), wider BOP range (±25G to ±100G), same SC59 package | Better suited for high-reliability automotive interior sensing where tighter hysteresis control is needed | Select if system requires lower magnetic threshold variation across voltage extremes (1.6V–5.5V) |
| MELEXIS US1881EUA-ABA-002-SP | Push-pull output, 2.5μA average current, identical BOP/BRP specs, same SC59 footprint | Eliminates external pull-up resistor but lacks wired-OR capability | Choose when board space is constrained and no bus-sharing is required |
Compared with A3212LLHLT-T and US1881EUA-ABA-002-SP, the AH1921-W-7 offers the lowest average current (1.6μA) and open-drain flexibility for multi-sensor buses - making it optimal for long-life, multi-node IoT deployments where power and wiring simplicity are prioritized.
Availability
AH1921-W-7 is available at Aetrix Electronics and suitable for smart cover detection, utility meter tamper sensing, and IoT end-node position sensing requiring stable component supply, full traceability, and long-term lifecycle support.
Supply support for AH1921-W-7 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
Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, specializing in power management, signal integrity, and sensor solutions for industrial, computing, and consumer markets.
The AH1921-W-7 belongs to Diodes' Hall-effect switch product line, engineered specifically for ultra-low-power magnetic sensing in battery-operated endpoints - emphasizing longevity, environmental robustness, and ease of integration into compact PCB layouts.
FAQ
What is the maximum recommended operating voltage for AH1921-W-7?
The absolute maximum supply voltage is 6V, but Diodes specifies 1.6V to 5.5V as the functional operating range. Operation above 5.5V risks permanent damage and violates the device's qualified reliability profile - sustained use at 5.5V is acceptable, but margin should be maintained for transient spikes.
Can AH1921-W-7 replace AH1911-W-7 directly on the same PCB?
No - although both share identical SC59 pinout and supply specifications, AH1911-W-7 has push-pull output while AH1921-W-7 uses open-drain. Direct replacement requires removing the external pull-up resistor and verifying MCU input compatibility with open-drain logic levels and rise time.
How does the hibernating clocking system affect response time?
The device wakes every 30–80ms to sample magnetic field; output state updates within 30–80μs after wake-up. This results in worst-case latency of ~80ms - sufficient for cover detection or meter tamper alerts, but unsuitable for real-time motor commutation or high-speed counting.
Is AH1921-W-7 compliant with RoHS 3 and REACH requirements?
Yes - AH1921-W-7 is fully RoHS 3 (EU Directive 2015/863/EU) compliant, lead-free, halogen-free (<900ppm Br/Cl, <1000ppm Sb), and meets REACH SVHC thresholds. Certificate of Compliance is available from Diodes Incorporated upon request with batch traceability.
AH1921-W-7 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Series:
- -
- Package/Case:
- TO-236-3, SC-59, SOT-23-3
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Function:
- Omnipolar Switch
- Technology:
- Hall Effect
- Polarization:
- North Pole, South Pole
- Sensing Range:
- ±9mT Trip, ±6.7mT Release
- Test Condition:
- -40°C ~ 85°C
- Voltage - Supply:
- 1.6V ~ 5.5V
- Current - Supply (Max):
- 3µA
- Current - Output (Max):
- 1mA
- Output Type:
- Open Drain
- Features:
- -
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SC-59-3
AH1921-W-7 FAQ
1.How can I place an order for AH1921-W-7 through Aetrix?
Please submit a Request for Quotation (RFQ) for AH1921-W-7 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 AH1921-W-7 reliable?
The price and inventory of AH1921-W-7 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AH1921-W-7 is usually 5 days.
3.What payment methods are accepted for AH1921-W-7?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AH1921-W-7 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AH1921-W-7?
AH1921-W-7 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AH1921-W-7 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 AH1921-W-7?
For technical support, including AH1921-W-7 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AH1921-W-7 requirements.
6.How does Aetrix verify that AH1921-W-7 is sourced from the original manufacturer or authorized distributors?
All AH1921-W-7 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 AH1921-W-7 meets industry standards.
7.What is the process for return or replacement of AH1921-W-7?
All AH1921-W-7 units undergo pre-shipment inspection (PSI). If there is an issue with AH1921-W-7, 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 AH1921-W-7 part is unused and in its original packaging.
Return procedure for AH1921-W-7:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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