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Taiwan Semiconductor Corporation SMF24A
- Part No.:
- SMF24A
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- SOD-123W
- Datasheet:
-
SMF24A.pdf
- Description:
- TVS DIODE 24VWM 38.9VC SOD123W
- Quantity:
- Payment:
- Shipping:
Inventory:16,400
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Product details
Overview
SMF24A from Taiwan Semiconductor is a unidirectional surface-mount transient voltage suppressor diode designed for high-energy ESD and surge protection in DC power rails and signal lines. It features a 24V working stand-off voltage (VWM), 26.7–29.5V breakdown voltage (VBR), 38.9V clamping voltage at 5.1A peak pulse current, and 200W peak pulse power handling per 10/1000μs waveform - deployed in automotive lighting control modules and industrial sensor interfaces.
For engineers reviewing the SMF24A datasheet, SMF24A pinout, SMF24A application, or SMF24A equivalent, key selection criteria include clamping performance under ISO 7637-2 Pulse 1/2a/2b/3a/3b, low leakage (<1μA @ 24V), SOD-123W package compatibility with automated placement, and junction temperature range of –55°C to +175°C for under-hood or motor-control environments.
Technical Context
The SMF24A operates as a unidirectional avalanche diode, triggered when reverse voltage exceeds its specified VBR range (26.7–29.5V). Its clamping action limits transients to ≤38.9V at 5.1A, enabling robust protection of downstream 24V logic and microcontroller I/O pins without latch-up or thermal runaway.
It meets ISO 7637-2 immunity requirements for automotive electronics and supports operation up to TJ = +175°C, with thermal resistance RθJL = 33°C/W and RθJA = 100°C/W on a 5mm × 5mm copper pad - confirming suitability for thermally constrained PCB layouts in engine control units and CAN node protection circuits.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 24 V - Maximum continuous reverse operating voltage before conduction begins; defines safe DC rail margin for 24V systems. |
| VBR min / max | 26.7 V / 29.5 V - Breakdown onset range at 1mA test current; ensures predictable turn-on across process variation. |
| VC @ IPPM | 38.9 V - Clamped voltage at 5.1A peak pulse (10/1000μs); guarantees protected IC sees <39V during worst-case surge. |
| PPPM | 200 W - Peak pulse power rating; supports high-energy transients per ISO 7637-2 Pulse 1 & 2b without degradation. |
| IR @ VWM | <1 μA - Reverse leakage at 24V; negligible power loss and no measurable loading on 24V supply rails. |
| TJ max | +175 °C - Maximum junction temperature; enables deployment in under-hood automotive locations and industrial motor drives. |
Pinout & Package
Package: SOD-123W - Surface-mount plastic case with matte tin-plated leads, UL 94V-0 rated molding compound, polarity indicated by cathode band, weight ≈ 0.016g.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal | Connected to lower-potential side (e.g., ground or return path) in unidirectional configuration. |
| Cathode | Reverse-biased protection terminal | Connected to protected line (e.g., 24V rail or signal input); conducts only during overvoltage events. |
Key Features
| Feature | Design Value |
|---|---|
| ISO 7637-2 compliance | Validated for Pulse 1, 2a, 2b, 3a, and 3b - enables drop-in use in automotive ECUs without additional filtering. |
| Low IR leakage | <1 μA @ VWM - eliminates standby current penalty and avoids false triggering in battery-powered systems. |
| Automated placement ready | SOD-123W footprint with J-STD-002 solderability - supports high-yield SMT assembly in volume production. |
| High-temperature operation | Junction rating up to +175°C - allows placement near heat sources (e.g., MOSFETs, inductors) without derating. |
Applications
| Automotive Lighting Control | Industrial Sensor Interface |
|---|---|
Use Scenario: Protecting LED driver ICs and CAN transceivers from load-dump and inductive switching spikes in headlamp modules. IC Role / Device Role / Timing Role: Unidirectional TVS placed between 24V rail and ground, clamping transients before they reach sensitive analog front-ends. Use Value: Limits voltage to ≤38.9V during 5.1A surges, preventing latch-up or permanent damage to 30V-rated drivers and transceivers. | Use Scenario: Safeguarding 4–20mA current-loop receivers and ADC inputs against EFT bursts in factory-floor pressure/temperature sensors. IC Role / Device Role / Timing Role: Standoff protection element on signal line input, absorbing fast transients while maintaining <1μA leakage at 24V nominal. Use Value: Enables reliable operation under IEC 61000-4-4 Level 4 (4kV) without signal distortion or baseline shift. |
| Motor Drive Power Stage | DC Power Rail Protection |
Use Scenario: Shielding gate drivers and bootstrap circuitry from flyback voltage spikes generated by brushed DC motor commutation. IC Role / Device Role / Timing Role: Clamp device across high-side switch supply rail, activated only during >26.7V overvoltage events. Use Value: Prevents overvoltage stress on 30V-rated gate drivers while adding zero propagation delay or signal loading. | Use Scenario: Guarding 24V input stages of PLC I/O modules against accidental reverse polarity and surge coupling from adjacent AC lines. IC Role / Device Role / Timing Role: Primary overvoltage suppression component on main DC input, placed upstream of fuse and DC-DC converter. Use Value: Absorbs 200W pulses without failure, maintaining system uptime and eliminating need for redundant protection layers. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| Littelfuse SMAJ24A | Same VWM (24V), identical SOD-123 package, but higher VC = 39.4V @ 5.1A and lower PPPM = 400W (derated to 200W at TA = 85°C) | Marginally higher clamping voltage; suitable where tighter VC tolerance is not critical | Prefer SMF24A when clamping voltage ≤38.9V is required for 30V-rated ICs |
| ON Semiconductor SMBJ24A | Same VWM and VBR range, but SMB package (larger footprint), higher RθJA = 125°C/W, and VC = 38.9V @ 5.5A | Requires PCB area increase; better suited for lower-density boards with thermal relief constraints | Choose SMF24A for space-constrained designs needing SOD-123W footprint and superior thermal resistance (RθJA = 100°C/W) |
Compared with SMAJ24A and SMBJ24A, the SMF24A delivers identical 24V standoff and clamping performance in a smaller SOD-123W package with lower thermal resistance - making it optimal for compact, high-temperature automotive and industrial modules where board space and thermal management are critical.
Availability
SMF24A is available at Aetrix Electronics and suitable for automotive lighting control, industrial sensor interface, and motor drive power stage applications requiring stable component supply, long-term lifecycle support, and RoHS/halogen-free compliance.
Supply support for SMF24A 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 semiconductor manufacturer specializing in discrete power devices, TVS diodes, rectifiers, and MOSFETs for automotive, industrial, and consumer markets.
The SMF24A belongs to TSC's SMF-series unidirectional TVS family, engineered specifically for high-reliability transient suppression in 12V/24V automotive and industrial systems - emphasizing low leakage, ISO 7637-2 compliance, and SMT manufacturability.
FAQ
What is the clamping voltage of the SMF24A and how is it measured?
The SMF24A has a maximum clamping voltage (VC) of 38.9 V, measured at a peak pulse current (IPPM) of 5.1 A using a 10/1000 μs waveform. This value is guaranteed across temperature and process variation per Taiwan Semiconductor's D2103 datasheet, and defines the upper voltage limit imposed on protected circuitry during surge events. The SMF24A maintains this clamping performance consistently in real-world 24V system protection applications.
Is the SMF24A suitable for automotive applications requiring ISO 7637-2 compliance?
Yes, the SMF24A is explicitly tested and rated to meet ISO 7637-2 for Pulse 1, 2a, 2b, 3a, and 3b waveforms - making it qualified for use in automotive electronic control units, lighting modules, and body electronics. Its 200W peak pulse power rating, low leakage, and +175°C junction rating align directly with OEM requirements for under-hood and chassis-mounted systems using the SMF24A.
What package type does the SMF24A use and what are its mounting characteristics?
The SMF24A uses the SOD-123W surface-mount package: a compact, lead-free, RoHS- and halogen-free molded case with matte tin-plated leads compliant with J-STD-002 solderability standards. Its 0.016g weight and UL 94V-0 flammability rating support high-speed automated placement and reflow compatibility - confirmed in the SMF24A ordering information and mechanical data sections of the official datasheet.
How does the SMF24A compare to bidirectional TVS diodes in 24V systems?
The SMF24A is unidirectional and optimized for DC rail protection where polarity is fixed - offering lower leakage (<1 μA @ 24V) and tighter VBR distribution than comparable bidirectional parts. Unlike bidirectional TVS diodes, the SMF24A does not conduct during normal reverse bias, making it ideal for 24V supply lines where reverse-voltage tolerance is not required. This characteristic improves efficiency and simplifies design validation for the SMF24A.
What is the maximum junction temperature rating for the SMF24A and why does it matter?
The SMF24A has a maximum junction temperature (TJ) rating of +175°C, verified per absolute maximum ratings in the datasheet. This enables reliable operation in high-ambient environments such as engine compartments, motor drives, and industrial enclosures - where thermal margins are tight. The SMF24A's RθJL = 33°C/W further supports sustained performance without derating, distinguishing it from lower-TJ alternatives in demanding deployments.
SMF24A 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):
- 24V
- Voltage - Breakdown (Min):
- 26.7V
- Voltage - Clamping (Max) @ Ipp:
- 38.9V
- Current - Peak Pulse (10/1000µs):
- 5.1A
- Power - Peak Pulse:
- 200W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 175°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOD-123W
SMF24A FAQ
1.How can I place an order for SMF24A through Aetrix?
Please submit a Request for Quotation (RFQ) for SMF24A 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 SMF24A reliable?
The price and inventory of SMF24A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMF24A is usually 5 days.
3.What payment methods are accepted for SMF24A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMF24A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMF24A?
SMF24A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMF24A 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 SMF24A?
For technical support, including SMF24A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMF24A requirements.
6.How does Aetrix verify that SMF24A is sourced from the original manufacturer or authorized distributors?
All SMF24A 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 SMF24A meets industry standards.
7.What is the process for return or replacement of SMF24A?
All SMF24A units undergo pre-shipment inspection (PSI). If there is an issue with SMF24A, 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 SMF24A part is unused and in its original packaging.
Return procedure for SMF24A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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