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Vishay General Semiconductor - Diodes Division SMBJ18CAHM3_B/I
- Part No.:
- SMBJ18CAHM3_B/I
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SMBJ18CAHM3_B/I.pdf
- Description:
- 600W,18V 5%,BIDIR,SMB TVS
- Quantity:
- Payment:
- Shipping:
Inventory:9,900
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Product details
Overview
SMBJ18CAHM3_B/I from Vishay General Semiconductor is a bidirectional surface-mount Transient Voltage Suppressor (TVS) diode in SMB (DO-214AA) package, designed for clamping voltage transients on signal and power lines. It features 18 V standoff voltage (VWM), 20.0–22.1 V breakdown voltage (VBR) at 1 mA, 600 W peak pulse power (10/1000 µs), and clamps to ≤29.2 V at 20.5 A peak surge current - deployed in industrial sensor interfaces and telecom line protection.
For engineers reviewing the SMBJ18CAHM3_B/I datasheet, SMBJ18CAHM3_B/I pinout, SMBJ18CAHM3_B/I application, or SMBJ18CAHM3_B/I equivalent, this device serves as a halogen-free, RoHS-compliant, AEC-Q101-qualified TVS for bidirectional overvoltage protection where low clamping voltage, fast response (<1 ns), and MSL Level 1 reflow compatibility are critical selection criteria.
Technical Context
This bidirectional TVS operates symmetrically across both polarities, with identical VBR min/max (20.0 V / 22.1 V), ID ≤1.0 µA at VWM = 18 V, and TC of VBR = 0.092 %/°C. Its junction-to-lead thermal resistance is 20 °C/W, enabling effective transient energy dissipation without external heatsinking under standard PCB pad layout (0.2" × 0.2").
The device complies with ANSI/IEEE C62.35 for surge suppression and meets UL 497B recognition (QVGQ2) for protector classification. It is rated for TJ = –55 °C to +150 °C and supports repetitive 0.01% duty cycle surges per 10/1000 µs waveform - validated for automotive-grade reliability via AEC-Q101 qualification (HM3 suffix).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 18 V - maximum continuous reverse operating voltage before clamping begins; defines safe working range for protected circuitry. |
| VBR (min/max) | 20.0 V / 22.1 V at IT = 1 mA - guaranteed breakdown onset window; ensures predictable turn-on during transients. |
| VC @ IPPM | 29.2 V at 20.5 A - clamped voltage during 10/1000 µs surge; determines maximum stress imposed on downstream ICs. |
| PPPM | 600 W - peak pulse power handling capability; enables robust protection against lightning-induced or inductive-switching surges. |
| ID @ VWM | ≤1.0 µA - ultra-low leakage at standoff voltage; prevents signal distortion or bias shift in high-impedance sensor paths. |
| TJ max. | +150 °C - maximum junction temperature; supports operation in under-hood automotive and industrial ambient environments. |
| Package | SMB (DO-214AA) - standardized surface-mount outline with 5.59 mm × 4.06 mm footprint and 2.20 mm height; compatible with automated placement. |
Pinout & Package
Package: SMB (DO-214AA), bidirectional configuration - no polarity marking; symmetrical terminals with cathode/anode roles interchangeable per direction of transient.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Transient current entry (negative polarity surge) | Accepts reverse surge current when voltage falls below –VBR; forms one half of bidirectional conduction path. |
| Cathode | Transient current entry (positive polarity surge) | Accepts forward surge current when voltage exceeds +VBR; completes symmetrical clamping behavior. |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional clamping | Enables single-device protection of AC-coupled or floating signal lines without polarity concerns - e.g., RS-485, CAN bus, Ethernet PHY interfaces. |
| 600 W peak pulse power (10/1000 µs) | Withstands high-energy transients from inductive load switching or ESD events while maintaining sub-30 V clamping voltage. |
| AEC-Q101 qualified (HM3 suffix) | Validated for automotive applications including body control modules and infotainment I/O protection - includes temperature cycling, HTRB, and ESD testing. |
| Halogen-free & RoHS-compliant | Meets environmental compliance requirements for industrial and consumer electronics without compromising surge performance or thermal reliability. |
| MSL Level 1 (260 °C peak) | Supports lead-free reflow soldering without moisture sensitivity concerns - eliminates bake preconditioning for production assembly. |
Applications
| Industrial Sensor Interface | Automotive Body Control Module |
|---|---|
|
Use Scenario: Protecting analog output lines of pressure/temperature sensors exposed to relay coil back-EMF in factory automation PLCs. IC Role / Device Role / Timing Role: Bidirectional voltage clamp placed directly at sensor connector to limit transients to <30 V before reaching ADC input stage. Use Value: Prevents ADC saturation and latch-up by clamping 600 W surges within 1 ns - preserving measurement integrity during machine startup/shutdown. |
Use Scenario: Safeguarding LIN bus transceiver I/O pins against load dump and jump-start induced spikes in door module ECUs. IC Role / Device Role / Timing Role: Standoff-limited TVS absorbing bidirectional surges on LIN data line while maintaining <1 µA leakage at 12 V system voltage. Use Value: Enables reliable communication during battery voltage excursions up to ±100 V without requiring additional filtering or isolation components. |
| Telecom Line Card Protection | Consumer USB-C Port ESD |
|
Use Scenario: Shielding Ethernet PHY differential pairs (e.g., RJ45 magnetics secondary side) from lightning-induced common-mode surges in PoE-powered switches. IC Role / Device Role / Timing Role: Paired SMBJ18CAHM3_B/I devices across TX+/TX– and RX+/RX– lines to suppress symmetric transients above ±20 V. Use Value: Maintains signal integrity with <2 pF junction capacitance at zero bias - avoids bandwidth degradation in 100BASE-TX applications. |
Use Scenario: Adding secondary-level ESD protection on USB-C CC and VCONN lines in portable docking stations subjected to IEC 61000-4-2 ±15 kV contact discharge. IC Role / Device Role / Timing Role: Low-leakage bidirectional clamp limiting voltage excursions to <29.2 V during fast-rising ESD events. Use Value: Complements primary TVS array by handling residual surges after initial current division - extends system-level ESD immunity beyond 8 kV. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar bidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ18CAHE3_B/I | Same electrical specs and SMB package, but RoHS-compliant commercial grade (not AEC-Q101 qualified); uses standard tin plating instead of whisker-tested matte tin. | Lacks automotive qualification; suitable for industrial/commercial designs where AEC-Q101 is not mandated. | Select when cost sensitivity outweighs automotive reliability requirements and MSL Level 1 reflow suffices. |
| SMCJ18CAHM3_A | Higher-power 1500 W version in larger SMC (DO-214AB) package; same VWM/VBR/VC ratings but 45.5 A IPPM and 20 °C/W RθJL. | Requires larger PCB area and higher thermal mass; used where surge energy exceeds 600 W limits. | Choose only if system-level surge testing requires >600 W margin - otherwise SMBJ18CAHM3_B/I offers optimal size/power balance. |
Compared with SMBJ18CAHE3_B/I, SMBJ18CAHM3_B/I adds AEC-Q101 qualification and whisker-resistant terminations for automotive use; versus SMCJ18CAHM3_A, it trades 2.5× surge power for 40% smaller footprint and lower parasitic capacitance - making SMBJ18CAHM3_B/I ideal for space-constrained, automotive-grade bidirectional protection.
Availability
SMBJ18CAHM3_B/I is available at Aetrix Electronics and suitable for industrial sensor interfaces, automotive body control modules, telecom line cards, and consumer USB-C port protection requiring stable component supply and full traceability.
Supply support for SMBJ18CAHM3_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, MOSFETs, optoelectronics, and passive components with emphasis on reliability, efficiency, and application-specific optimization.
The SMBJ series delivers standardized, high-reliability TVS diodes optimized for board-level transient suppression in automotive, industrial, and communications systems - balancing clamping performance, package scalability, and qualification rigor.
FAQ
What is the clamping voltage of SMBJ18CAHM3_B/I at its rated peak pulse current?
The SMBJ18CAHM3_B/I clamps to a maximum of 29.2 V at its specified peak pulse current of 20.5 A under the 10/1000 µs waveform condition. This value is measured per ANSI/IEEE C62.35 and reflects worst-case voltage seen by protected circuitry during surge events - critical for ensuring downstream ICs remain within absolute maximum ratings. The SMBJ18CAHM3_B/I achieves this with minimal incremental surge resistance and fast sub-nanosecond response.
Is SMBJ18CAHM3_B/I suitable for automotive applications?
Yes, SMBJ18CAHM3_B/I is AEC-Q101 qualified (denoted by HM3 suffix) and specifically designed for automotive use, including body control modules, infotainment I/O, and LIN/CAN bus protection. It undergoes rigorous stress testing - including temperature cycling, highly accelerated life testing (HALT), and ESD validation - and supports reflow up to 260 °C (MSL Level 1). The SMBJ18CAHM3_B/I also features whisker-resistant matte tin terminations compliant with JESD 201 Class 2.
How does SMBJ18CAHM3_B/I differ from unidirectional SMBJ18A variants?
SMBJ18CAHM3_B/I is bidirectional with symmetrical clamping behavior in both polarities, while SMBJ18A is unidirectional and conducts only during positive surges (cathode-biased). The "CA" suffix confirms bidirectionality, enabling protection of AC-coupled or floating lines without polarity constraints. Electrically, SMBJ18CAHM3_B/I has identical VWM (18 V) and VBR (20.0–22.1 V), but differs in leakage (1.0 µA vs. 5.0 µA for SMBJ18A) and lacks IFSM rating - reflecting its dual-path conduction architecture.
What is the thermal resistance and maximum operating temperature of SMBJ18CAHM3_B/I?
SMBJ18CAHM3_B/I has a typical junction-to-lead thermal resistance (RθJL) of 20 °C/W and a maximum junction temperature (TJ max.) of +150 °C. Its junction-to-ambient thermal resistance (RθJA) is 100 °C/W when mounted on minimum recommended copper pads (0.2" × 0.2"). These values enable reliable operation in high-ambient environments such as engine compartments or enclosed industrial enclosures - provided PCB layout adheres to Vishay's pad recommendations to maintain thermal performance.
Does SMBJ18CAHM3_B/I require special PCB layout considerations?
Yes - optimal performance requires mounting SMBJ18CAHM3_B/I on 0.2" × 0.2" (5.0 mm × 5.0 mm) copper pads per terminal, as specified in the Vishay datasheet (Document Number: 88392). Smaller pads increase thermal impedance and reduce surge current handling; inadequate copper area may cause premature failure during repetitive transients. The SMBJ18CAHM3_B/I's low-profile SMB package also demands precise stencil design for consistent solder paste deposition to avoid tombstoning during reflow.
SMBJ18CAHM3_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:
- -
- Bidirectional Channels:
- 1
- 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)
SMBJ18CAHM3_B/I FAQ
1.How can I place an order for SMBJ18CAHM3_B/I through Aetrix?
Please submit a Request for Quotation (RFQ) for SMBJ18CAHM3_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 SMBJ18CAHM3_B/I reliable?
The price and inventory of SMBJ18CAHM3_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 SMBJ18CAHM3_B/I is usually 5 days.
3.What payment methods are accepted for SMBJ18CAHM3_B/I?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMBJ18CAHM3_B/I transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMBJ18CAHM3_B/I?
SMBJ18CAHM3_B/I orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMBJ18CAHM3_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 SMBJ18CAHM3_B/I?
For technical support, including SMBJ18CAHM3_B/I datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMBJ18CAHM3_B/I requirements.
6.How does Aetrix verify that SMBJ18CAHM3_B/I is sourced from the original manufacturer or authorized distributors?
All SMBJ18CAHM3_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 SMBJ18CAHM3_B/I meets industry standards.
7.What is the process for return or replacement of SMBJ18CAHM3_B/I?
All SMBJ18CAHM3_B/I units undergo pre-shipment inspection (PSI). If there is an issue with SMBJ18CAHM3_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 SMBJ18CAHM3_B/I part is unused and in its original packaging.
Return procedure for SMBJ18CAHM3_B/I:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMBJ18CAHM3_B/I Tags
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