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Taiwan Semiconductor Corporation SMF22AH
- Part No.:
- SMF22AH
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- SOD-123W
- Datasheet:
-
SMF22AH.pdf
- Description:
- TVS DIODE 22VWM 35.5VC SOD123W
- Quantity:
- Payment:
- Shipping:
Inventory:5,968
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Product details
Overview
SMF22AH from Taiwan Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode in SOD-123W package, rated for 22 V working stand-off voltage, 24.4–26.9 V breakdown voltage at 1 mA, 5.6 A peak pulse current (10/1000 µs), and 35.5 V clamping voltage under surge. It delivers 200 W peak pulse power and meets ISO 7637-2 Pulse 1/2a/2b/3a/3b for automotive load-dump and switching transient protection.
For engineers reviewing the SMF22AH datasheet, SMF22AH pinout, SMF22AH application, or SMF22AH equivalent, key selection criteria include its AEC-Q101 qualification, low 1 µA max reverse leakage above 10 V, 175 °C junction temperature rating, SOD-123W footprint compatibility with automated placement, and verified clamping performance in 12 V automotive subsystems.
Technical Context
The SMF22AH operates as a unidirectional avalanche diode, activated when reverse voltage exceeds its 24.4–26.9 V breakdown threshold. Its clamping action limits transients to ≤35.5 V at 5.6 A, protecting downstream ICs during load dump or inductive kick events.
Designed for automotive-grade reliability, it features glass-passivated junction, JESD201 Class 2 whisker resistance, moisture sensitivity level 1, and compliance with ISO 7637-2 test pulses-enabling direct integration into 12 V battery rail protection circuits without derating at ambient temperatures up to 125 °C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 22 V - Maximum continuous reverse operating voltage before clamping begins |
| VBR min/max | 24.4 V / 26.9 V at IT = 1 mA - Confirmed avalanche onset range for reliable turn-on margin |
| VC @ IPPM | 35.5 V at IPPM = 5.6 A (10/1000 µs) - Peak voltage seen by protected circuit during worst-case surge |
| PPPM | 200 W - Surge energy handling capacity per single transient event |
| IR @ VWM | <1 µA - Negligible leakage current ensures minimal standby power loss in always-on systems |
| TJ max | 175 °C - Enables operation in under-hood environments with high thermal stress |
| Package | SOD-123W - Standardized 2-pin surface-mount outline with 5 mm × 5 mm copper pad thermal requirement |
Pinout & Package
SMF22AH uses the SOD-123W package: a compact, molded surface-mount case with matte tin-plated leads, polarity indicated by cathode band, and weight of 0.016 g. Thermal performance is characterized with 5 mm × 5 mm Cu pad PCB mounting (RθJA = 100 °C/W, RθJL = 33 °C/W).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction path | Connected to system ground or lower-potential node in unidirectional configuration |
| Cathode | Transient clamping node | Connected to protected line (e.g., 12 V rail); conducts avalanche current during overvoltage |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive electronics use including engine control, body modules, and infotainment power rails |
| Glass-passivated junction | Ensures long-term stability and corrosion resistance in humid or chemically aggressive environments |
| ISO 7637-2 compliance | Guarantees robustness against real-world automotive transients: Pulse 1 (inductive switch-off), Pulse 2a/2b (load dump), Pulse 3a/3b (switching noise) |
| Low IR <1 µA @ VWM | Minimizes quiescent current draw in always-on vehicle networks (e.g., CAN bus wake-up circuits) |
| SOD-123W footprint | Enables high-density PCB layout and compatibility with standard pick-and-place equipment for mass production |
Applications
| Automotive Body Control Module (BCM) | LED Headlamp Driver Protection |
|---|---|
Use Scenario: Protects microcontroller I/O and power supply inputs from load dump and relay coil flyback in door module, seat control, and lighting switches. IC Role / Device Role / Timing Role: Unidirectional TVS placed between 12 V rail and ground, clamping surges before they reach LDOs or MCU VDD pins. Use Value: Prevents latch-up or permanent damage during 12 V system transients up to ±100 V, validated per ISO 7637-2 Pulse 2b. | Use Scenario: Shields constant-current LED driver ICs from inductive kick generated by PWM-controlled buck converters and external MOSFET switches. IC Role / Device Role / Timing Role: Fast-response clamping device on input rail, limiting voltage overshoot to ≤35.5 V during 5.6 A transient events. Use Value: Maintains LED driver functionality across >100,000 switching cycles without degradation, supported by 175 °C TJ rating. |
| Infotainment Power Supply Input | 12 V Telematics ECU Protection |
Use Scenario: Guards USB-C PD controller, audio codec, and display interface power inputs against battery line disturbances during cold-crank or jump-start conditions. IC Role / Device Role / Timing Role: Primary overvoltage clamp on main 12 V input, coordinated with upstream fuse and downstream ceramic filtering. Use Value: Limits clamped voltage to 35.5 V while sustaining 200 W peak power, preserving signal integrity and preventing brownout resets. | Use Scenario: Secures LTE/GNSS modem power and CAN FD transceiver VCC lines against electrical fast transients (EFT) and electrostatic discharge in connected car gateways. IC Role / Device Role / Timing Role: Unidirectional TVS on 12 V auxiliary rail, providing sub-100 ns response to 4 kV ESD events per IEC 61000-4-2. Use Value: Achieves <1 µA leakage at 22 V, eliminating standby current impact on battery drain in always-connected telematics units. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ22A | Same VWM (22 V), but higher VC = 36.2 V at 5.4 A; SOD-123 (not SOD-123W) package with slightly smaller thermal pad area | Limited to non-AEC-Q101 industrial designs; lower thermal performance (RθJA ≈ 125 °C/W) | Acceptable for cost-sensitive consumer applications where AEC-Q101 and ISO 7637-2 are not required |
| P6SMB22A | Higher PPPM = 600 W, but larger DO-214AA package; VWM = 22 V, VC = 35.5 V at 17 A (10/1000 µs) | Used in higher-energy surge environments (e.g., alternator output); requires larger PCB area and manual rework capability | Preferred when system-level surge testing exceeds 200 W or when board space allows larger footprint |
Compared with SMAJ22A and P6SMB22A, the SMF22AH offers optimal balance of AEC-Q101 qualification, SOD-123W manufacturability, and precise 35.5 V clamping-making it the preferred choice for space-constrained, automotive-compliant 12 V rail protection where thermal management and automated assembly are critical.
Availability
SMF22AH is available at Aetrix Electronics and suitable for automotive body electronics, LED lighting drivers, infotainment power supplies, and telematics ECUs requiring stable component supply with full traceability and lifecycle support.
Supply support for SMF22AH 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
Taiwan Semiconductor Corporation (TSC) is a vertically integrated analog and discrete semiconductor manufacturer headquartered in Hsinchu, Taiwan, serving global automotive, industrial, and consumer markets since 1979.
The SMF22AH belongs to TSC's AEC-Q101-qualified SMF series of surface-mount TVS diodes, engineered specifically for robust, high-reliability transient suppression in 12 V and 24 V automotive power networks.
FAQ
What is the breakdown voltage range of the SMF22AH?
The SMF22AH has a guaranteed breakdown voltage range of 24.4 V to 26.9 V at a test current of 1 mA, as specified in the official Taiwan Semiconductor datasheet revision A2103. This range ensures consistent avalanche initiation across production lots and temperature extremes, directly supporting design margin calculations for 12 V automotive systems where SMF22AH is deployed.
Is the SMF22AH suitable for automotive applications?
Yes, the SMF22AH is AEC-Q101 qualified and explicitly tested to meet ISO 7637-2 Pulse 1, 2a, 2b, 3a, and 3b standards-making it suitable for front-end protection in automotive body control modules, lighting systems, and telematics ECUs. Its 175 °C maximum junction temperature and glass-passivated junction further validate its suitability for under-hood and high-reliability vehicle applications.
What is the clamping voltage of the SMF22AH under surge conditions?
The SMF22AH clamps to a maximum of 35.5 V when subjected to a 10/1000 µs surge waveform with a peak current of 5.6 A. This value is measured and guaranteed per the manufacturer's electrical specifications table and defines the upper voltage limit imposed on protected circuitry during transient events-critical for ensuring downstream ICs remain within their absolute maximum ratings.
Does the SMF22AH have a unidirectional or bidirectional configuration?
The SMF22AH is a unidirectional TVS diode, designed to protect DC circuits with defined polarity-such as 12 V automotive power rails. Its datasheet specifies only reverse breakdown parameters (VBR, VWM, VC), no symmetrical bidirectional characteristics. The cathode band marking confirms polarity orientation, and it must be installed with cathode toward the protected line and anode to ground.
What package type does the SMF22AH use, and what are its thermal requirements?
The SMF22AH uses the SOD-123W surface-mount package, featuring matte tin-plated leads and a polarity-indicating cathode band. For rated thermal performance (RθJA = 100 °C/W), it requires mounting on a 5 mm × 5 mm copper pad per lead on the PCB. This layout is essential to sustain its 200 W peak pulse power rating and prevent junction overheating during repetitive transient events.
SMF22AH Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Taiwan Semiconductor Corporation
- Package/Case:
- SOD-123W
- Series:
- SMF
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 22V
- Voltage - Breakdown (Min):
- 24.4V
- Voltage - Clamping (Max) @ Ipp:
- 35.5V
- Current - Peak Pulse (10/1000µs):
- 5.6A
- Power - Peak Pulse:
- 200W
- Power Line Protection:
- No
- Applications:
- -
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 175°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOD-123W
SMF22AH FAQ
1.How can I place an order for SMF22AH through Aetrix?
Please submit a Request for Quotation (RFQ) for SMF22AH 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 SMF22AH reliable?
The price and inventory of SMF22AH are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMF22AH is usually 5 days.
3.What payment methods are accepted for SMF22AH?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMF22AH transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMF22AH?
SMF22AH orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMF22AH 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 SMF22AH?
For technical support, including SMF22AH datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMF22AH requirements.
6.How does Aetrix verify that SMF22AH is sourced from the original manufacturer or authorized distributors?
All SMF22AH 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 SMF22AH meets industry standards.
7.What is the process for return or replacement of SMF22AH?
All SMF22AH units undergo pre-shipment inspection (PSI). If there is an issue with SMF22AH, 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 SMF22AH part is unused and in its original packaging.
Return procedure for SMF22AH:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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