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Taiwan Semiconductor Corporation SMF70AH
- Part No.:
- SMF70AH
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- SOD-123W
- Datasheet:
-
SMF70AH.pdf
- Description:
- TVS DIODE 70VWM 113VC SOD123W
- Quantity:
- Payment:
- Shipping:
Inventory:7,531
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Product details
Overview
SMF70AH from Taiwan Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode designed for automotive-grade circuit protection. It features a 70 V working stand-off voltage (VWM), 77.8–86 V breakdown voltage (VBR), 113 V clamping voltage (VC) at 1.55 A peak pulse current, and 200 W peak pulse power (10/1000 µs waveform). It is AEC-Q101 qualified and used to protect automotive lighting control modules against ISO 7637-2 pulses.
For engineers reviewing the SMF70AH datasheet, SMF70AH pinout, SMF70AH application, or SMF70AH equivalent, key selection criteria include clamping performance under 10/1000 µs transients, low leakage (<1 µA @ 70 V), SOD-123W package compatibility with automated assembly, and compliance with automotive EFT and load-dump immunity standards.
Technical Context
The SMF70AH operates as a unidirectional avalanche diode, conducting only in reverse bias above its breakdown threshold to shunt transient energy to ground. Its glass-passivated junction ensures stable VBR tolerance and low leakage, while the SOD-123W package provides optimized thermal resistance (RθJL = 33 °C/W) for high-reliability PCB mounting.
It meets ISO 7637-2 Pulse 1 (inductive switch-off), Pulse 2a/2b (battery disconnection & coupling), and Pulse 3a/3b (EFT), with clamping validated at 113 V for 1.55 A IPPM - enabling robust protection of 70 V-rated CAN transceivers, LIN drivers, and microcontroller I/O pins without overvoltage stress.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 70 V - Maximum continuous reverse operating voltage before conduction begins; defines system operating margin. |
| VBR min/max | 77.8 V / 86 V - Breakdown occurs within this range at 1 mA test current; ensures predictable turn-on timing. |
| VC @ IPPM | 113 V - Clamped voltage during 1.55 A 10/1000 µs surge; limits downstream IC stress below safe thresholds. |
| PPPM | 200 W - Peak pulse power handling per 10/1000 µs waveform; supports automotive load-dump and EFT events. |
| IR @ VWM | <1 µA - Reverse leakage at rated stand-off voltage; prevents standby power loss in battery-critical systems. |
| TJ max | +175 °C - Maximum junction temperature; enables operation in under-hood automotive environments. |
| Package | SOD-123W - Surface-mount outline with enhanced thermal pad; compatible with standard reflow profiles and J-STD-002 soldering. |
Pinout & Package
SOD-123W package: molded plastic case with matte tin-plated leads, cathode indicated by band, polarity-sensitive mounting, weight ≈ 0.016 g, UL 94V-0 rated compound.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal | Connected to protected line (e.g., CAN_H); conducts during forward surges or DC bias conditions. |
| Cathode | Reverse conduction terminal | Connected to ground or low-impedance return path; initiates clamping when reverse voltage exceeds VBR. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualification | Validated for automotive use across temperature, humidity, and mechanical stress cycles - required for under-hood deployment. |
| Glass-passivated junction | Ensures stable VBR tolerance and <1 µA IR at VWM - critical for long-term reliability in 12 V/24 V systems. |
| ISO 7637-2 compliance | Passes Pulse 1, 2a, 2b, 3a, and 3b waveforms - protects against real-world automotive transients including load dump and inductive kick. |
| Low RθJL | 33 °C/W junction-to-lead thermal resistance - enables efficient heat transfer to PCB copper pads during repetitive surges. |
Applications
| Automotive Lighting Control | CAN Bus Node Protection |
|---|---|
Use Scenario: Protecting LED driver ICs and MOSFET gate drivers in headlamp modules subjected to load-dump transients. IC Role / Device Role / Timing Role: Unidirectional TVS placed between supply rail and ground to clamp voltage spikes before they reach sensitive logic. Use Value: Limits peak voltage to 113 V during 200 W surges, preventing latch-up or gate oxide damage in 70 V-rated drivers. | Use Scenario: Safeguarding CAN transceiver inputs (CAN_H/CAN_L) against ESD and coupled noise in body control units. IC Role / Device Role / Timing Role: Bidirectional clamping not required; SMF70AH used on VCC rail to prevent supply rail collapse during Pulse 3b fast transients. Use Value: Sub-µA leakage preserves bus idle state integrity; 113 V clamping avoids transceiver shutdown during 10/1000 µs bursts. |
| Industrial Sensor Interface | 12 V Power Rail Protection |
Use Scenario: Shielding analog front-end amplifiers and ADC references in automotive pressure sensors exposed to ignition noise. IC Role / Device Role / Timing Role: TVS placed on sensor VDD line to absorb sub-millisecond transients induced by nearby solenoid switching. Use Value: 70 V VWM allows full operation across cold-crank (6.5 V) to load-dump (up to 35 V) conditions while clamping >77.8 V events. | Use Scenario: Guarding microcontroller power domains in telematics modules where 12 V input feeds LDOs and PMICs. IC Role / Device Role / Timing Role: Primary overvoltage clamp on main 12 V input rail upstream of regulation stages. Use Value: 200 W PPPM rating handles worst-case ISO 7637-2 Pulse 1 (−100 V, 50 Ω source) without degradation after repeated events. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ70A | Higher PPPM (600 W), larger SMB package (vs. SOD-123W), higher VC (115 V) | Better suited for higher-energy transients but requires more board area and has slower response due to higher junction capacitance | Select SMBJ70A only if system-level testing confirms need for >200 W surge handling and PCB layout accommodates SMB footprint |
| P6SMB70A | Same SMB package as SMBJ70A, identical electrical specs, but lower AEC-Q101 adoption rate in automotive supply chains | Limited traceability for PPAP documentation; less common in Tier-1 automotive BOMs than SMF70AH | Prefer SMF70AH for new automotive designs requiring full AEC-Q101 documentation and SOD-123W space constraints |
Compared with SMBJ70A and P6SMB70A, the SMF70AH delivers equivalent 70 V clamping performance in a 40% smaller SOD-123W footprint, supports automated placement with J-STD-002-compliant terminations, and carries full AEC-Q101 qualification evidence - making it optimal for space-constrained, high-volume automotive electronics.
Availability
SMF70AH is available at Aetrix Electronics and suitable for automotive lighting control, CAN bus node protection, and 12 V power rail protection requiring stable component supply, full AEC-Q101 traceability, and SOD-123W packaging for high-density PCB layouts.
Supply support for SMF70AH 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, and rectifiers with global automotive and industrial certifications.
The SMF70AH belongs to TSC's AEC-Q101-qualified SMF-AH series of unidirectional TVS diodes, engineered specifically for ISO 7637-2-compliant transient suppression in automotive 12 V/24 V subsystems.
FAQ
What is the maximum clamping voltage of the SMF70AH under standard test conditions?
The SMF70AH exhibits a maximum clamping voltage (VC) of 113 V when subjected to a 10/1000 µs transient waveform at 1.55 A peak pulse current (IPPM). This value is measured per JEDEC standards and reflects the actual voltage seen by downstream components during surge events - ensuring protected ICs remain within their absolute maximum ratings.
Is the SMF70AH suitable for bidirectional transient protection?
No, the SMF70AH is a unidirectional TVS diode and is not rated for bidirectional clamping. It conducts only in reverse bias above its breakdown voltage and must be oriented with cathode toward the protected line's ground reference. For bidirectional protection, a dedicated bidirectional device such as SMAJ70A would be required instead of SMF70AH.
Does the SMF70AH meet automotive reliability standards?
Yes, the SMF70AH is fully AEC-Q101 qualified and tested for temperature cycling, humidity, mechanical shock, and solderability per JESD22 and J-STD-020. It also complies with ISO 7637-2 Pulse 1, 2a, 2b, 3a, and 3b - confirming its suitability for under-hood and body-control module applications where SMF70AH is deployed.
What is the reverse leakage current specification for SMF70AH at its working voltage?
The SMF70AH specifies a maximum reverse leakage current (IR) of 1 µA when biased at its 70 V working stand-off voltage (VWM) and tested at 25 °C. This ultra-low leakage ensures minimal impact on battery drain in always-on automotive circuits and maintains signal integrity in high-impedance sensor interfaces where SMF70AH is applied.
Can SMF70AH be used in place of SMF64AH or SMF75AH in a design?
SMF70AH is not a direct replacement for SMF64AH (64 V VWM) or SMF75AH (75 V VWM) due to its specific 70 V stand-off rating. Substituting requires verifying that system operating voltage tolerances, transient thresholds, and clamping margins align - for example, SMF70AH may be used where nominal 12 V systems experience up to 70 V during cold-crank or load-dump, but SMF70AH must not be swapped without recalculating worst-case clamping margins relative to protected IC ratings.
SMF70AH 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):
- 70V
- Voltage - Breakdown (Min):
- 77.8V
- Voltage - Clamping (Max) @ Ipp:
- 113V
- Current - Peak Pulse (10/1000µs):
- 1.55A
- 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
SMF70AH FAQ
1.How can I place an order for SMF70AH through Aetrix?
Please submit a Request for Quotation (RFQ) for SMF70AH 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 SMF70AH reliable?
The price and inventory of SMF70AH are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMF70AH is usually 5 days.
3.What payment methods are accepted for SMF70AH?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMF70AH transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMF70AH?
SMF70AH orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMF70AH 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 SMF70AH?
For technical support, including SMF70AH datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMF70AH requirements.
6.How does Aetrix verify that SMF70AH is sourced from the original manufacturer or authorized distributors?
All SMF70AH 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 SMF70AH meets industry standards.
7.What is the process for return or replacement of SMF70AH?
All SMF70AH units undergo pre-shipment inspection (PSI). If there is an issue with SMF70AH, 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 SMF70AH part is unused and in its original packaging.
Return procedure for SMF70AH:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMF70AH Tags
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