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Vishay General Semiconductor - Diodes Division SM6T18AHM3/I
- Part No.:
- SM6T18AHM3/I
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SM6T18AHM3/I.pdf
- Description:
- TVS DIODE 15.3VWM 25.2VC DO214AA
- Quantity:
- Payment:
- Shipping:
Inventory:2,489
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Product details
Overview
SM6T18AHM3/I from Vishay General Semiconductor is a unidirectional transient voltage suppressor (TVS) diode in SMB (DO-214AA) package, designed for clamping voltage transients on power and signal lines. It features 18 V breakdown voltage (VBR = 17.1–18.9 V at 1.0 mA), 15.3 V stand-off voltage (VWM), 25.2 V max clamping voltage (VC) at 24.0 A peak pulse current, and 600 W peak pulse power (10/1000 μs). It is halogen-free, RoHS-compliant, and qualified to AEC-Q101 for automotive electronics protection.
For engineers reviewing the SM6T18AHM3/I datasheet, SM6T18AHM3/I pinout, SM6T18AHM3/I application, or SM6T18AHM3/I equivalent, key selection criteria include its unidirectional polarity, 150 °C max junction temperature, low 20 °C/W junction-to-lead thermal resistance, and suitability for ESD/surge protection in automotive sensor interfaces, DC power rails, and industrial I/O circuits.
Technical Context
The SM6T18AHM3/I operates as a silicon avalanche diode with glass-passivated junction, delivering precise clamping during fast-rising transients. Its 10/1000 μs waveform response ensures robust protection against inductive switching surges and lightning-induced spikes up to 600 W.
Designed for surface-mount assembly on 0.2" × 0.2" copper pads, it achieves low inductance and meets MSL Level 1 per J-STD-020 with 260 °C reflow peak. The cathode band marking identifies polarity, and its SMB package supports automated placement without lead bending.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VBR (min/max) | 17.1 V / 18.9 V at 1.0 mA - defines reliable avalanche initiation threshold under standardized test conditions |
| VWM | 15.3 V - maximum continuous reverse voltage before leakage exceeds 1.0 μA, ensuring no conduction during normal operation |
| VC @ IPPM | 25.2 V at 24.0 A (10/1000 μs) - clamping voltage seen by protected circuit during worst-case surge event |
| PPPM | 600 W - peak transient power handling capability, critical for surviving ISO 7637-2 Pulse 1/2a/5a in automotive systems |
| TJ max. | +150 °C - enables reliable operation in under-hood automotive environments and high-ambient industrial settings |
| RθJL | 20 °C/W - low junction-to-lead thermal resistance supports sustained power dissipation without excessive temperature rise |
Pinout & Package
Package: SMB (DO-214AA), surface-mount, halogen-free, RoHS-compliant, with matte tin-plated leads solderable per J-STD-002. Cathode identified by black band.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Current entry terminal in forward bias; connected to system ground or low-side reference | Provides return path during transient clamping; must be routed with low-inductance trace to minimize voltage overshoot |
| Cathode | Current exit terminal in forward bias; marked with band; connected to protected line | Defines clamping polarity-applies suppression only when protected line rises above VWM relative to ground |
Key Features
| Feature | Design Value |
|---|---|
| 600 W peak pulse power (10/1000 μs) | Enables single-device protection against severe load-dump and inductive kick events in 12 V automotive systems |
| AEC-Q101 qualified (HM3 suffix) | Validated for automotive-grade reliability including temperature cycling, humidity testing, and mechanical shock per stress test requirements |
| Low 20 °C/W RθJL | Reduces thermal bottleneck between die and PCB pad, improving surge endurance over repeated transient events |
| Glass-passivated junction | Ensures stable VBR and low leakage over time and temperature, critical for long-life embedded applications |
Applications
| Automotive Sensor Protection | Industrial DC Power Rail Clamping |
|---|---|
Use Scenario: Protecting CAN/LIN bus transceivers and analog sensor outputs (e.g., pressure, temperature) from ESD and load-dump transients in engine control units. IC Role / Device Role / Timing Role: Unidirectional TVS diode placed between signal line and chassis ground to clamp positive-going surges above 15.3 V. Use Value: Prevents latch-up or damage to 3.3 V/5 V interface ICs while maintaining signal integrity below VWM, validated per ISO 10605 and ISO 7637-2. | Use Scenario: Safeguarding 12 V or 24 V DC input rails of PLC modules, motor drivers, and power supplies against inductive switching spikes. IC Role / Device Role / Timing Role: Primary overvoltage clamp located at board-level input connector, shunting surge energy to ground before reaching downstream regulators. Use Value: Limits rail voltage excursion to ≤25.2 V during 24 A transient, preserving input capacitor lifetime and preventing regulator shutdown or failure. |
| Consumer Device USB Port Protection | Telecom Line Interface Surge Suppression |
Use Scenario: Adding secondary-level surge immunity to USB VBUS and D+/D− lines in set-top boxes, routers, and smart home hubs. IC Role / Device Role / Timing Role: Standoff-rated TVS array component used alongside common-mode chokes and ESD diodes to meet IEC 61000-4-5 Level 3 (1 kV/2 kA). Use Value: Absorbs differential-mode surges up to 600 W without degrading USB 2.0 signal integrity due to low capacitance and fast response (<1 ns). | Use Scenario: Protecting Ethernet PHY or RS-485 transceivers in outdoor base stations and network switches exposed to lightning-induced surges on twisted-pair lines. IC Role / Device Role / Timing Role: First-stage unidirectional clamp on powered line (e.g., PoE midspan), referenced to local ground plane. Use Value: Withstands repetitive 10/1000 μs surges up to 24 A while maintaining <1 μA leakage at 15.3 V, reducing false triggers in high-noise telecom environments. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ18A | Same VWM (15.3 V) and VC (25.2 V), but rated for 400 W PPPM and not AEC-Q101 qualified | Limited to commercial-grade industrial or consumer use; lacks automotive qualification and halogen-free compliance | Select SMAJ18A only for cost-sensitive non-automotive designs where 400 W surge margin suffices |
| 1.5SMC18A | Higher PPPM (1500 W), larger SMC package (DO-214AB), same VBR range but higher VC (29.2 V) | Requires more PCB area; clamps at higher voltage, risking downstream IC stress unless derated | Choose 1.5SMC18A only when 1500 W surge rating is mandatory and layout allows SMC footprint |
Compared with SMAJ18A and 1.5SMC18A, the SM6T18AHM3/I delivers automotive-grade reliability in a compact SMB package with optimal 25.2 V clamping-making it the preferred choice for space-constrained, AEC-Q101–required applications where 600 W surge handling is sufficient.
Availability
SM6T18AHM3/I is available at Aetrix Electronics and suitable for automotive sensor interfaces, industrial DC power rails, and telecom line protection requiring stable component supply, halogen-free compliance, and AEC-Q101 qualification.
Supply support for SM6T18AHM3/I 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
Vishay General Semiconductor is a global leader in discrete semiconductors, specializing in diodes, rectifiers, MOSFETs, and protection devices with emphasis on reliability, efficiency, and application-specific performance.
The SM6T Series is engineered for robust transient suppression in harsh environments-targeting automotive, industrial, and telecom systems where consistent clamping behavior, thermal stability, and qualification to AEC-Q101 are mandatory design requirements.
FAQ
What is the breakdown voltage tolerance for SM6T18AHM3/I?
The SM6T18AHM3/I has a specified breakdown voltage (VBR) range of 17.1 V to 18.9 V at 1.0 mA test current, representing ±5.6% tolerance around the nominal 18 V rating. This tight tolerance ensures predictable clamping onset across production lots and temperature ranges, critical for protecting sensitive 15 V-tolerant interfaces without premature conduction.
Is SM6T18AHM3/I suitable for bidirectional transient suppression?
No, SM6T18AHM3/I is a unidirectional TVS diode, indicated by the "A" suffix and cathode band marking. For bidirectional protection, Vishay offers the SM6T18CA variant (with "CA" suffix), which provides symmetrical clamping in both polarities. Using SM6T18AHM3/I in bidirectional applications risks failure during negative transients.
What does the "HM3" suffix signify in SM6T18AHM3/I?
The "HM3" suffix in SM6T18AHM3/I denotes halogen-free, RoHS-compliant construction with AEC-Q101 qualification. The "H" indicates automotive grade, "M" confirms halogen-free materials, and "3" specifies the packaging format (tape-and-reel). The "/I" denotes 13-inch reel delivery with 3200 units per reel.
How does SM6T18AHM3/I perform under elevated ambient temperatures?
SM6T18AHM3/I's peak pulse power is derated linearly above 25 °C ambient, per Figure 2 in the datasheet. At 85 °C, its 600 W rating drops to approximately 420 W. Its 150 °C maximum junction temperature and 20 °C/W RθJL allow sustained operation in hot environments when mounted on adequate copper area (0.2" × 0.2" pads minimum).
Can SM6T18AHM3/I replace SMAJ18A in an existing design?
SM6T18AHM3/I is not a direct drop-in replacement for SMAJ18A due to differences in qualification and thermal performance: SM6T18AHM3/I is AEC-Q101 qualified and has lower RθJL (20 vs. 30 °C/W), but identical VWM, VBR, and VC. Layout compatibility is confirmed (both SMB), but validation of surge margin and automotive compliance is required before substitution.
SM6T18AHM3/I Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Package/Case:
- DO-214AA, SMB
- Series:
- SM6T, TransZorb®
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Discontinued at Digi-Key
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 15.3V
- Voltage - Breakdown (Min):
- 17.1V
- Voltage - Clamping (Max) @ Ipp:
- 25.2V
- Current - Peak Pulse (10/1000µs):
- 24A
- Power - Peak Pulse:
- 600W
- Power Line Protection:
- No
- Applications:
- -
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -65°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AA (SMB)
SM6T18AHM3/I FAQ
1.How can I place an order for SM6T18AHM3/I through Aetrix?
Please submit a Request for Quotation (RFQ) for SM6T18AHM3/I 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 SM6T18AHM3/I reliable?
The price and inventory of SM6T18AHM3/I are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SM6T18AHM3/I is usually 5 days.
3.What payment methods are accepted for SM6T18AHM3/I?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM6T18AHM3/I transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SM6T18AHM3/I?
SM6T18AHM3/I orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SM6T18AHM3/I 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 SM6T18AHM3/I?
For technical support, including SM6T18AHM3/I datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM6T18AHM3/I requirements.
6.How does Aetrix verify that SM6T18AHM3/I is sourced from the original manufacturer or authorized distributors?
All SM6T18AHM3/I 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 SM6T18AHM3/I meets industry standards.
7.What is the process for return or replacement of SM6T18AHM3/I?
All SM6T18AHM3/I units undergo pre-shipment inspection (PSI). If there is an issue with SM6T18AHM3/I, 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 SM6T18AHM3/I part is unused and in its original packaging.
Return procedure for SM6T18AHM3/I:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SM6T18AHM3/I Tags
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