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Vishay General Semiconductor - Diodes Division SMBJ18AHM3_B/I
- Part No.:
- SMBJ18AHM3_B/I
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SMBJ18AHM3_B/I.pdf
- Description:
- 600W,18V 5%,UNIDIR,SMB TVS
- Quantity:
- Payment:
- Shipping:
Inventory:8,347
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Product details
Overview
SMBJ18AHM3_B/I from Vishay General Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode in SMB (DO-214AA) package, designed for clamping fast-rising ESD and surge transients on power and signal lines. It features 18 V stand-off voltage (VWM), 29.2 V maximum clamping voltage (VC) at 20.5 A peak pulse current (IPPM), and 600 W peak pulse power (PPPM) with 10/1000 µs waveform - deployed in automotive sensor interfaces, industrial I/O protection, and DC power rail surge suppression.
For engineers reviewing the SMBJ18AHM3_B/I datasheet, SMBJ18AHM3_B/I pinout, SMBJ18AHM3_B/I application, or SMBJ18AHM3_B/I equivalent, this page delivers verified electrical specs, thermal derating behavior, AEC-Q101 qualification status, and real-world clamping performance data essential for robust overvoltage design in automotive and industrial systems.
Technical Context
This TVS diode operates as a unidirectional avalanche clamp, triggered when reverse voltage exceeds its 20.0–22.1 V breakdown range (VBR) at 1 mA test current. Its low incremental surge resistance ensures stable clamping under repetitive 10/1000 µs surges up to 0.01% duty cycle, while the glass-passivated junction enables fast response time (<1 ns) and reliable operation across -55 °C to +150 °C junction temperature range.
The device is halogen-free and RoHS-compliant (HM3 suffix), qualified to AEC-Q101 for automotive use, and rated for MSL Level 1 per J-STD-020 with 260 °C reflow peak. Its SMB package provides 100 °C/W junction-to-ambient thermal resistance on standard 0.2" × 0.2" copper pads, supporting high-reliability placement in automated SMT lines.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM (Stand-off Voltage) | 18 V - Maximum continuous reverse working voltage before clamping begins; defines safe operating margin below breakdown. |
| VBR (Breakdown Voltage) | 20.0–22.1 V at 1 mA - Confirmed avalanche onset range; ensures predictable turn-on during transients. |
| VC (Clamping Voltage) | 29.2 V at IPPM = 20.5 A - Peak voltage seen by protected circuit during 10/1000 µs surge; critical for IC-level survivability. |
| PPPM (Peak Pulse Power) | 600 W - Sustained energy absorption capability under standardized 10/1000 µs waveform; validates surge rating per IEC 61000-4-5. |
| ID (Reverse Leakage) | 1.0 µA max at VWM - Minimal standby current leakage; preserves low-power system integrity. |
| TJ max. | +150 °C - Maximum junction temperature; supports operation in under-hood automotive and high-ambient industrial environments. |
| Package | SMB (DO-214AA) - Standardized surface-mount outline with cathode band marking; compatible with JEDEC MS-012AC footprint. |
Pinout & Package
Package: SMB (DO-214AA), molded plastic case with matte tin-plated leads, MSL Level 1, 260 °C reflow peak. Cathode indicated by band on body end.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal | Connected to ground or lower-potential rail in unidirectional configuration; carries forward surge current during clamping. |
| Cathode | Reverse-biased clamping terminal | Connected to protected line (e.g., 12 V rail or sensor output); initiates avalanche conduction when Vreverse > VBR. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive-grade reliability including temperature cycling, HTRB, and surge endurance - required for engine control, ADAS, and body electronics. |
| 600 W peak pulse power | Withstands IEC 61000-4-5 Level 4 (4 kV) surge events on 12 V/24 V systems without degradation. |
| Halogen-free & RoHS-compliant (HM3) | Meets automotive environmental compliance mandates (e.g., ELV, REACH) and supports lead-free assembly processes. |
| Low clamping ratio (VC/VBR ≈ 1.42) | Minimizes overvoltage stress on downstream ICs - critical for protecting 3.3 V or 5 V logic interfaces connected via level-shifting circuits. |
| Fast response time (<1 ns) | Engages before transient energy couples into sensitive circuitry - essential for safeguarding high-speed CAN, LIN, or analog sensor signals. |
Applications
| Automotive Sensor Protection | Industrial PLC I/O Protection |
|---|---|
|
Use Scenario: Protecting analog outputs of pressure/temperature sensors in engine bay modules exposed to load dump and ISO 7637-2 pulses. IC Role / Device Role / Timing Role: Unidirectional TVS placed between sensor VOUT and ground to clamp negative transients and limit positive overshoot to ≤29.2 V. Use Value: Prevents latch-up or gate oxide damage in downstream op-amps and ADC front-ends during 12 V rail disturbances. |
Use Scenario: Shielding digital input channels on programmable logic controllers from field-induced surges in factory automation wiring. IC Role / Device Role / Timing Role: Mounted at connector entry point to shunt induced common-mode transients before reaching optocoupler or Schmitt trigger inputs. Use Value: Maintains signal integrity during 2 kV/10/700 µs telecom surges while enabling >1 million surge cycles without parameter drift. |
| DC Power Rail Clamping | USB/CAN Transceiver Protection |
|
Use Scenario: Secondary overvoltage protection on 12 V or 24 V board-level power distribution networks downstream of primary DC-DC converters. IC Role / Device Role / Timing Role: Parallel-connected TVS absorbing residual transients escaping upstream filters and ferrites during load switching. Use Value: Limits rail excursion to <29.2 V, preventing brownout resets or undervoltage lockout in microcontrollers and PMICs. |
Use Scenario: Bidirectional protection not applicable; SMBJ18AHM3_B/I used in unidirectional CANH line protection where ground-referenced clamping is sufficient. IC Role / Device Role / Timing Role: Placed between CANH and chassis ground to clamp positive spikes while allowing normal differential signaling. Use Value: Preserves CAN bus timing margins by limiting clamping delay to sub-nanosecond, avoiding bit error rate degradation. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ18AHE3_B/I | Same electrical specs, but RoHS-compliant (E3) without halogen-free certification; no AEC-Q101 qualification. | Suitable for commercial/industrial designs where automotive qualification is not mandated. | Select when halogen-free content is not required and cost sensitivity outweighs automotive compliance. |
| SMAJ18A-M3 | Lower PPPM (400 W), higher VC (32.4 V at 12.4 A), SMA package (smaller footprint, higher RθJA = 140 °C/W). | Limited to lower-energy transients; less effective in high-ambient or high-surge environments. | Choose only for space-constrained boards with ≤400 W surge exposure and ambient <85 °C. |
Compared with SMBJ18AHM3_B/I, the SMBJ18AHE3_B/I offers identical clamping performance without halogen-free assurance or AEC-Q101 validation, while the SMAJ18A-M3 trades surge robustness and thermal margin for smaller size - making SMBJ18AHM3_B/I the optimal choice for automotive-critical and high-reliability industrial deployments.
Availability
SMBJ18AHM3_B/I is available at Aetrix Electronics and suitable for automotive sensor interfaces, industrial PLC I/O protection, and DC power rail clamping requiring stable component supply, long-term lifecycle support, and traceable sourcing.
Supply support for SMBJ18AHM3_B/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 optimization.
The SMBJ series targets high-energy transient suppression in automotive, industrial, and telecom infrastructure - engineered for AEC-Q101 compliance, robust surge handling, and seamless SMT integration.
FAQ
What is the clamping voltage of SMBJ18AHM3_B/I at its rated peak pulse current?
The SMBJ18AHM3_B/I has a maximum clamping voltage (VC) of 29.2 V at its specified peak pulse current (IPPM) of 20.5 A under a 10/1000 µs waveform. This value is measured per IEC 61000-4-5 test conditions and defines the upper voltage limit imposed on protected circuitry during surge events. The SMBJ18AHM3_B/I maintains this clamping performance across its full operating temperature range (-55 °C to +150 °C), ensuring consistent protection in harsh environments.
Is SMBJ18AHM3_B/I qualified for automotive applications?
Yes, SMBJ18AHM3_B/I is AEC-Q101 qualified, as confirmed by Vishay's ordering code suffix "HM3_B/I", where "HM3" denotes halogen-free, RoHS-compliant, and AEC-Q101-qualified construction. This qualification covers stress tests including temperature cycling, high-temperature reverse bias (HTRB), and surge endurance - validating SMBJ18AHM3_B/I for use in engine control units, body electronics, and ADAS modules.
What does the "HM3" suffix mean in SMBJ18AHM3_B/I?
The "HM3" suffix in SMBJ18AHM3_B/I indicates halogen-free, RoHS-compliant construction with AEC-Q101 qualification. It distinguishes this variant from "E3" (RoHS-compliant only) and "HE3" (RoHS + AEC-Q101, non-halogen-free). The "B/I" denotes packaging: "B" is the revision code, and "I" specifies 13-inch tape-and-reel delivery with 3200 units per reel - optimized for high-volume SMT assembly.
How does SMBJ18AHM3_B/I differ from bidirectional TVS diodes like SMBJ18CA?
SMBJ18AHM3_B/I is unidirectional and functions as a single-polarity clamp - conducting only in reverse breakdown (cathode-to-anode) and blocking forward current above ~3.5 V. In contrast, SMBJ18CA is bidirectional, providing symmetrical clamping for AC-coupled or floating lines. SMBJ18AHM3_B/I is preferred for DC power rails and grounded-signal lines where polarity is fixed and higher surge margin is needed; SMBJ18CA suits differential buses like RS-485 or antenna feeds.
What is the thermal resistance of SMBJ18AHM3_B/I, and how does it affect layout?
SMBJ18AHM3_B/I has a typical junction-to-ambient thermal resistance (RθJA) of 100 °C/W when mounted on 0.2" × 0.2" (5.0 mm × 5.0 mm) copper pads per terminal. This value assumes minimum recommended pad layout per Vishay's datasheet. To maintain safe junction temperatures during repetitive surges, PCB layout must provide adequate copper area and avoid thermal bottlenecks - undersized traces or insufficient thermal vias will elevate RθJA and risk exceeding the +150 °C TJ max.
SMBJ18AHM3_B/I Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Package/Case:
- DO-214AA, SMB
- Series:
- TransZorb®
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 18V
- Voltage - Breakdown (Min):
- 20V
- Voltage - Clamping (Max) @ Ipp:
- 29.2V
- Current - Peak Pulse (10/1000µs):
- 20.5A
- Power - Peak Pulse:
- 600W
- Power Line Protection:
- No
- Applications:
- Telecom
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AA (SMB)
SMBJ18AHM3_B/I FAQ
1.How can I place an order for SMBJ18AHM3_B/I through Aetrix?
Please submit a Request for Quotation (RFQ) for SMBJ18AHM3_B/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 SMBJ18AHM3_B/I reliable?
The price and inventory of SMBJ18AHM3_B/I are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMBJ18AHM3_B/I is usually 5 days.
3.What payment methods are accepted for SMBJ18AHM3_B/I?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMBJ18AHM3_B/I transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMBJ18AHM3_B/I?
SMBJ18AHM3_B/I orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMBJ18AHM3_B/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 SMBJ18AHM3_B/I?
For technical support, including SMBJ18AHM3_B/I datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMBJ18AHM3_B/I requirements.
6.How does Aetrix verify that SMBJ18AHM3_B/I is sourced from the original manufacturer or authorized distributors?
All SMBJ18AHM3_B/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 SMBJ18AHM3_B/I meets industry standards.
7.What is the process for return or replacement of SMBJ18AHM3_B/I?
All SMBJ18AHM3_B/I units undergo pre-shipment inspection (PSI). If there is an issue with SMBJ18AHM3_B/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 SMBJ18AHM3_B/I part is unused and in its original packaging.
Return procedure for SMBJ18AHM3_B/I:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMBJ18AHM3_B/I Tags
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