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Taiwan Semiconductor Corporation SMF12AH
- Part No.:
- SMF12AH
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- SOD-123W
- Datasheet:
-
SMF12AH.pdf
- Description:
- TVS DIODE 12VWM 19.9VC SOD123W
- Quantity:
- Payment:
- Shipping:
Inventory:2,476
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Product details
Overview
SMF12AH from Taiwan Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode designed for automotive-grade ESD and surge protection. It features a 12 V working stand-off voltage (VWM), 13.3–14.7 V breakdown voltage (VBR), 19.9 V clamping voltage (VC) at 10.1 A peak pulse current, and 200 W peak pulse power (10/1000 µs). It is used to protect CAN/LIN bus interfaces, automotive lighting controllers, and microcontroller I/O pins against ISO 7637-2 Pulse 1/2a/2b/3a/3b transients.
For engineers reviewing the SMF12AH datasheet, SMF12AH pinout, SMF12AH application, or SMF12AH equivalent, key selection criteria include clamping performance under 10/1000 µs surge, AEC-Q101 qualification status, SOD-123W package thermal resistance (RθJL = 33 °C/W), and low reverse leakage (<1 µA @ 12 V) in automotive ambient temperature ranges.
Technical Context
The SMF12AH operates as a unidirectional avalanche diode with glass-passivated junction for stable breakdown behavior and high reliability in harsh environments. Its clamping action begins above 13.3 V (min VBR) and limits transient voltages to ≤19.9 V at 10.1 A, enabling robust protection of 12 V automotive electronics without overvoltage stress on downstream ICs.
It meets ISO 7637-2 test requirements for vehicle electrical systems-including Pulse 1 (inductive load dump suppression), Pulse 2a (sudden load disconnect), and Pulse 3a/3b (capacitive coupling transients)-and is rated for continuous operation from −55 °C to +175 °C junction temperature.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 12 V - Maximum continuous reverse operating voltage before conduction begins; matches nominal 12 V automotive supply rails. |
| VBR (min/max) | 13.3 / 14.7 V - Breakdown occurs within this range at 1 mA test current; ensures reliable turn-on margin above VWM. |
| VC @ IPPM | 19.9 V @ 10.1 A - Clamped voltage during 10/1000 µs surge; keeps protected ICs below absolute maximum ratings. |
| PPPM | 200 W - Peak pulse power handling capability; supports high-energy transients per ISO 7637-2. |
| IR @ VWM | <1 µA - Negligible leakage at 12 V; avoids battery drain in always-on automotive modules. |
| TJ max | +175 °C - Enables placement near heat sources (e.g., power stages, engine compartments) without derating. |
| RθJL | 33 °C/W - Low junction-to-lead thermal resistance; facilitates efficient heat transfer to PCB copper pads. |
Pinout & Package
Package: SOD-123W - Surface-mount plastic case with matte tin-plated leads, UL 94V-0 molding compound, and cathode band polarity marking. Weight: 0.016 g. Moisture sensitivity level: J-STD-020 Level 1.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Low-side reference terminal | Connected to ground or low-voltage return path; forms forward-biased path during positive transients on cathode side. |
| Cathode | Protected line input | Connected to signal/power line requiring protection; avalanche conduction occurs from cathode to anode during overvoltage events. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive use per stress test requirements including HTOL, TCT, and ESD-HBM/MM, ensuring long-term reliability in vehicle ECUs. |
| Glass-passivated junction | Stable VBR tolerance and low parameter drift over temperature and lifetime, critical for consistent clamping in safety-critical systems. |
| ISO 7637-2 compliance | Passes Pulse 1 (−150 V/0.5 Ω), Pulse 2a (+100 V/2 Ω), and Pulse 3a/b (±25 V/50 Ω) waveforms-enabling drop-in protection for 12 V CAN/LIN networks. |
| SOD-123W footprint | Compatible with standard automated pick-and-place equipment; enables high-yield assembly in automotive manufacturing lines. |
| Low IR & high TJ max | Sub-1 µA leakage at 12 V and +175 °C rating allow use in always-on modules (e.g., body control units) without thermal or power budget penalties. |
Applications
| Automotive CAN Bus Protection | LED Headlamp Driver Protection |
|---|---|
Use Scenario: Protecting CAN_H/CAN_L lines in body control modules from load dump and inductive switching transients. IC Role / Device Role / Timing Role: Unidirectional TVS placed between CAN_H and ground, clamping negative-going pulses while allowing normal differential signaling. Use Value: Limits transient voltage to ≤19.9 V, preventing damage to CAN transceivers rated for 40 V absolute maximum, and maintaining bus integrity during ISO 7637-2 Pulse 1 events. | Use Scenario: Safeguarding LED driver ICs and MOSFET gate drivers in adaptive front-lighting systems (AFS) from inductive kickback. IC Role / Device Role / Timing Role: Connected across driver output and ground to absorb energy from relay/coil switching spikes. Use Value: Withstands 200 W peak pulse power and clamps at 19.9 V, protecting 20 V-rated gate drivers and preserving PWM timing accuracy during rapid dimming transitions. |
| Infotainment System USB Port | Engine Control Unit (ECU) Sensor Inputs |
Use Scenario: ESD protection for USB 2.0 data lines (D+/D−) in head unit applications exposed to human contact. IC Role / Device Role / Timing Role: Dual-channel layout using two SMF12AH devices (one per line) referenced to chassis ground. Use Value: Sub-1 µA leakage preserves signal integrity at 480 Mbps; clamping response <1 ns prevents latch-up in USB PHY transceivers during ±8 kV HBM ESD events. | Use Scenario: Shielding analog sensor inputs (e.g., MAP, O2, coolant temp) from alternator ripple and ignition noise. IC Role / Device Role / Timing Role: Placed at connector interface to shunt transients before reaching precision ADC front-end. Use Value: 12 V VWM aligns with sensor supply rails; 19.9 V VC ensures analog input stays within 0–5 V ADC range even during 100 V/50 Ω Pulse 3b surges. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ12A | Same VWM (12 V), but higher VC (23.2 V @ 8.5 A); lower PPPM (400 W); SMA package (larger footprint, RθJA = 65 °C/W). | Less effective clamping for sensitive 3.3 V/5 V logic; requires larger PCB area; better suited for non-automotive industrial use. | Select SMAJ12A only if higher surge margin is needed and space/thermal constraints allow SMA package. |
| TPSMA6L12A | Lower IR (0.5 µA), tighter VBR tolerance (13.3–14.4 V), same VC (19.9 V); also AEC-Q101 qualified; identical SOD-123W package. | Offers improved consistency in mass production; preferred where tighter parametric control is required for functional safety compliance. | TPSMA6L12A is a direct form-fit-function alternative with enhanced process control; suitable for ASIL-B designs requiring tighter VBR distribution. |
Compared with SMAJ12A and TPSMA6L12A, the SMF12AH delivers optimal balance of automotive qualification, compact SOD-123W footprint, and precise 19.9 V clamping-making it ideal for space-constrained ECU nodes where thermal management and ISO 7637-2 margin are critical.
Availability
SMF12AH is available at Aetrix Electronics and suitable for automotive electronic control units, LED lighting systems, and infotainment interfaces requiring stable component supply across extended temperature and high-reliability environments.
Supply support for SMF12AH 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, with global distribution and AEC-Q101-compliant production lines.
The SMF series was developed specifically for automotive transient suppression, targeting ISO 7637-2 compliance, high-temperature operation, and automated SMT assembly-addressing design needs in modern 12 V/24 V vehicle architectures.
FAQ
What is the clamping voltage of SMF12AH under a 10/1000 µs surge?
The SMF12AH has a maximum clamping voltage (VC) of 19.9 V when subjected to a 10/1000 µs waveform at its rated peak pulse current of 10.1 A. This value is measured per JEDEC standards and confirmed in the official Taiwan Semiconductor datasheet revision A2103. The clamping performance ensures protected circuits remain within safe operating limits during ISO 7637-2 Pulse 1 and Pulse 2a events. SMF12AH maintains this specification across its full operating temperature range.
Is SMF12AH qualified for automotive applications?
Yes, SMF12AH is AEC-Q101 qualified, having passed all required stress tests including high-temperature operating life (HTOL), temperature cycling (TCT), and electrostatic discharge (HBM/MM). It is explicitly intended for automotive use and meets ISO 7637-2 immunity requirements for Pulses 1, 2a, 2b, 3a, and 3b. Taiwan Semiconductor's certification documentation confirms SMF12AH's suitability in engine control units, body modules, and lighting systems.
What package does SMF12AH use, and is it compatible with standard SMT processes?
SMF12AH uses the SOD-123W surface-mount package, featuring matte tin-plated leads compliant with J-STD-002 solderability standards and JESD 201 Class 2 whisker resistance. Its dimensions and pad layout align with IPC-7351B recommendations, making it fully compatible with high-speed pick-and-place equipment and reflow profiles used in automotive electronics manufacturing. The SOD-123W footprint is smaller than SMA but offers comparable thermal performance due to optimized leadframe design.
How does SMF12AH compare to SMF12A in terms of specifications?
SMF12AH is the AEC-Q101 qualified version of the SMF12A series, with identical electrical parameters (VWM = 12 V, VBR = 13.3–14.7 V, VC = 19.9 V) but enhanced reliability validation. Unlike SMF12A, SMF12AH undergoes automotive-specific qualification testing, includes tighter process controls, and is marked with "AH" suffix per ordering code. Both share the SOD-123W package, but only SMF12AH is approved for use in safety-critical automotive modules per OEM requirements.
What is the maximum junction temperature rating for SMF12AH?
The SMF12AH has a maximum junction temperature (TJ) rating of +175 °C, verified per absolute maximum ratings in the Taiwan Semiconductor datasheet. This allows operation in under-hood environments and near power components without thermal derating. The device's RθJL of 33 °C/W and RθJA of 100 °C/W (on 5 mm × 5 mm Cu pad) support sustained performance at elevated ambient temperatures, making SMF12AH suitable for engine control units and transmission control modules where thermal margins are tight.
SMF12AH 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):
- 12V
- Voltage - Breakdown (Min):
- 13.3V
- Voltage - Clamping (Max) @ Ipp:
- 19.9V
- Current - Peak Pulse (10/1000µs):
- 10.1A
- 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
SMF12AH FAQ
1.How can I place an order for SMF12AH through Aetrix?
Please submit a Request for Quotation (RFQ) for SMF12AH 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 SMF12AH reliable?
The price and inventory of SMF12AH are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMF12AH is usually 5 days.
3.What payment methods are accepted for SMF12AH?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMF12AH transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMF12AH?
SMF12AH orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMF12AH 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 SMF12AH?
For technical support, including SMF12AH datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMF12AH requirements.
6.How does Aetrix verify that SMF12AH is sourced from the original manufacturer or authorized distributors?
All SMF12AH 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 SMF12AH meets industry standards.
7.What is the process for return or replacement of SMF12AH?
All SMF12AH units undergo pre-shipment inspection (PSI). If there is an issue with SMF12AH, 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 SMF12AH part is unused and in its original packaging.
Return procedure for SMF12AH:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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