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Vishay General Semiconductor - Diodes Division SMB8J18CAHM3_A/I
- Part No.:
- SMB8J18CAHM3_A/I
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SMB8J18CAHM3_A/I.pdf
- Description:
- TVS DIODE 18VWM 29.2VC DO214AA
- Quantity:
- Payment:
- Shipping:
Inventory:4,805
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Product details
Overview
SMB8J18CAHM3_A/I from Vishay General Semiconductor is a bidirectional transient voltage suppressor (TVS) diode in SMB (DO-214AA) package, designed for high-energy surge protection on signal and power lines. It features a 18 V stand-off voltage (VWM), 29.2 V maximum clamping voltage (VC) at 27.4 A peak pulse current (IPPM), and 800 W peak pulse power (PPPM) with 10/1000 µs waveform - deployed in automotive sensor interfaces and industrial I/O protection.
For engineers reviewing the SMB8J18CAHM3_A/I datasheet, SMB8J18CAHM3_A/I pinout, SMB8J18CAHM3_A/I application, or SMB8J18CAHM3_A/I equivalent, key selection criteria include bidirectional clamping capability, AEC-Q101 qualification, low clamping ratio (VC/VWM ≈ 1.62), MSL Level 1 moisture sensitivity, and halogen-free RoHS compliance per HM3 suffix.
Technical Context
This TVS diode operates as a voltage-clamped shunt protector, responding within <1 ps to transients induced by inductive switching or ESD events. Its glass-passivated junction ensures stable breakdown behavior, while the bidirectional configuration enables symmetrical clamping across both polarities without external polarity management.
Designed for surface-mount automation, it uses matte tin-plated leads compliant with J-STD-002 and JESD 22-B102, and meets JESD 201 Class 2 whisker resistance. Thermal resistance is RθJA = 72 °C/W (typ.) and RθJL = 20 °C/W (typ.), supporting operation from –55 °C to +150 °C junction temperature.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 18 V - maximum continuous reverse operating voltage before clamping initiates |
| VBR min/max | 20.0 V / 22.1 V at 1 mA - precise breakdown threshold ensuring reliable turn-on margin |
| VC @ IPPM | 29.2 V at 27.4 A - limits downstream voltage stress during 800 W transient events |
| PPPM | 800 W (10/1000 µs) - energy-handling capacity suitable for ISO 7637-2 Pulse 1/2a/5a automotive transients |
| ID @ VWM | 1.0 µA - ultra-low leakage preserves signal integrity in high-impedance sensor lines |
| TJ max | +150 °C - supports under-hood automotive environments and industrial enclosures |
| AEC-Q101 | Qualified - validated for automotive electronics reliability per stress test requirements |
| Package | SMB (DO-214AA) - 0.220" × 0.130" footprint compatible with standard SMT reflow profiles |
Pinout & Package
SMB8J18CAHM3_A/I is housed in an SMB (DO-214AA) surface-mount package with two terminals: cathode and anode. As a bidirectional device, it has no polarity marking; both terminals are functionally symmetric for AC-coupled or differential line protection.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | AC input terminal | Accepts transient energy from either polarity; connects to protected line (e.g., CAN_H or LIN) |
| Cathode | AC input terminal | Completes symmetrical clamping path; ties to same reference as Anode (no ground reference required) |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional clamping | Enables single-device protection of AC signals, differential buses (e.g., RS-485, CAN), and ungrounded sensor outputs without polarity concerns |
| AEC-Q101 qualification | Validates robustness for automotive applications including engine control modules, body electronics, and ADAS sensor interfaces |
| Halogen-free & RoHS-compliant (HM3) | Meets global environmental regulations and supports lead-free reflow assembly with J-STD-020 MSL Level 1 rating (260 °C peak) |
| Low clamping ratio (VC/VWM = 1.62) | Minimizes overvoltage exposure to downstream ICs such as microcontrollers or transceivers during surge events |
| Glass-passivated junction | Ensures stable VBR over lifetime and temperature, reducing parameter drift in harsh industrial or automotive environments |
Applications
| Automotive Sensor Interface | Industrial RS-485 Bus |
|---|---|
Use Scenario: Protecting analog output lines of pressure/temperature sensors in engine bay modules exposed to load dump and ISO 7637-2 transients. IC Role / Device Role: Shunt TVS placed between sensor signal line and chassis ground to clamp surges before reaching ADC input. Use Value: SMB8J18CAHM3_A/I's 29.2 V clamping voltage prevents damage to 3.3 V or 5 V sensor signal conditioning circuitry during 800 W pulses. | Use Scenario: Safeguarding RS-485 transceiver data lines (A/B) against ESD and lightning-induced surges in factory automation PLCs. IC Role / Device Role: Bidirectional TVS connected differentially across A–B lines to suppress common-mode and differential-mode transients. Use Value: Symmetrical clamping maintains signal integrity on full-duplex bus; 1.0 µA leakage avoids bias current errors in high-impedance termination networks. |
| Consumer USB Port Protection | Smart Meter Power Line Interface |
Use Scenario: Guarding USB 2.0 D+/D– lines in portable medical devices against contact ESD per IEC 61000-4-2 ±15 kV air discharge. IC Role / Device Role: Low-capacitance TVS mounted directly at connector to minimize stub length and preserve signal rise time. Use Value: SMB8J18CAHM3_A/I's fast response (<1 ps) and 29.2 V clamping prevent latch-up in USB PHY ICs without degrading 480 Mbps data eye. | Use Scenario: Protecting AC mains-sensing inputs in smart electricity meters subjected to surge coupling from distribution lines. IC Role / Device Role: Front-end TVS on isolated voltage divider network feeding metering ASIC. Use Value: 800 W PPPM rating handles combination wave surges (1.2/50 µs + 8/20 µs); 150 °C TJ max ensures reliability in sealed, thermally constrained meter housings. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMB8J18CAHE3_A/I | RoHS-compliant but not halogen-free; same electrical specs and AEC-Q101 qualification | Preferred for commercial-grade automotive modules where halogen content is unrestricted | Select when cost optimization is prioritized over halogen-free requirement |
| SMAJ18CA-M3 | Lower PPPM (400 W), SMA package (smaller footprint, higher RθJA), same VWM/VC | Suitable for space-constrained consumer electronics with lower surge immunity needs | Choose only if system-level testing confirms 400 W suffices and thermal margin allows higher junction temperature rise |
Compared with SMB8J18CAHM3_A/I, SMB8J18CAHE3_A/I offers identical protection performance with non-halogen-free construction, while SMAJ18CA-M3 trades 50 % lower surge power and reduced thermal performance for smaller board area - neither is pin-compatible due to differing SMB vs. SMA footprints.
Availability
SMB8J18CAHM3_A/I is available at Aetrix Electronics and suitable for automotive sensor protection, industrial communication bus hardening, and smart meter front-end surge suppression requiring stable component supply and AEC-Q101 assurance.
Supply support for SMB8J18CAHM3_A/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 and application-specific performance.
The SMB8JxxCA series belongs to Vishay's TRANSZORB® TVS platform, engineered specifically for high-power-density, AEC-Q101-qualified transient suppression in automotive and industrial environments where robustness and repeatable clamping are critical.
FAQ
What is the clamping voltage of SMB8J18CAHM3_A/I at its rated peak pulse current?
The SMB8J18CAHM3_A/I exhibits a maximum clamping voltage (VC) of 29.2 V when subjected to its rated peak pulse current (IPPM) of 27.4 A using the standardized 10/1000 µs waveform. This value is measured per ANSI/IEEE C62.35 and defines the upper voltage limit imposed on protected circuitry during surge events - critical for ensuring compatibility with 3.3 V or 5 V interface ICs downstream.
Is SMB8J18CAHM3_A/I suitable for automotive applications?
Yes, SMB8J18CAHM3_A/I is AEC-Q101 qualified and explicitly designated for automotive use via its HM3 suffix (halogen-free, RoHS-compliant, AEC-Q101). It meets stringent stress tests for temperature cycling, humidity, mechanical shock, and surge endurance - making it appropriate for engine control units, body control modules, and ADAS sensor interfaces where reliability under harsh conditions is mandatory.
How does the bidirectional configuration of SMB8J18CAHM3_A/I affect its PCB layout?
The bidirectional nature of SMB8J18CAHM3_A/I eliminates polarity marking - both terminals are functionally identical, allowing placement across any two points needing symmetrical overvoltage protection (e.g., differential bus lines like CAN_H/CAN_L or RS-485 A/B). No orientation check is required during automated placement, simplifying layout and reducing assembly error risk compared to unidirectional TVS diodes.
What is the maximum operating temperature for SMB8J18CAHM3_A/I?
SMB8J18CAHM3_A/I has a maximum junction temperature (TJ max) of +150 °C and operates across –55 °C to +150 °C. This range supports deployment in under-hood automotive locations, industrial motor drives, and enclosed smart meter housings where ambient temperatures may exceed 105 °C - provided board-level thermal design maintains junction temperature within limit using recommended 0.2" × 0.2" copper pads per terminal.
Does SMB8J18CAHM3_A/I require a heatsink for standard operation?
No, SMB8J18CAHM3_A/I does not require an external heatsink under normal transient conditions. Its thermal resistance (RθJA = 72 °C/W typ.) is designed for operation with standard PCB copper pad areas (0.2" × 0.2" per terminal). Heatsinking is unnecessary unless subjected to repetitive high-duty-cycle surges - in which case thermal simulation or empirical testing is recommended to verify sustained junction temperature remains below +150 °C.
SMB8J18CAHM3_A/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:
- Obsolete
- 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):
- 27.4A
- Power - Peak Pulse:
- 800W
- 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)
SMB8J18CAHM3_A/I FAQ
1.How can I place an order for SMB8J18CAHM3_A/I through Aetrix?
Please submit a Request for Quotation (RFQ) for SMB8J18CAHM3_A/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 SMB8J18CAHM3_A/I reliable?
The price and inventory of SMB8J18CAHM3_A/I are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMB8J18CAHM3_A/I is usually 5 days.
3.What payment methods are accepted for SMB8J18CAHM3_A/I?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMB8J18CAHM3_A/I transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMB8J18CAHM3_A/I?
SMB8J18CAHM3_A/I orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMB8J18CAHM3_A/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 SMB8J18CAHM3_A/I?
For technical support, including SMB8J18CAHM3_A/I datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMB8J18CAHM3_A/I requirements.
6.How does Aetrix verify that SMB8J18CAHM3_A/I is sourced from the original manufacturer or authorized distributors?
All SMB8J18CAHM3_A/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 SMB8J18CAHM3_A/I meets industry standards.
7.What is the process for return or replacement of SMB8J18CAHM3_A/I?
All SMB8J18CAHM3_A/I units undergo pre-shipment inspection (PSI). If there is an issue with SMB8J18CAHM3_A/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 SMB8J18CAHM3_A/I part is unused and in its original packaging.
Return procedure for SMB8J18CAHM3_A/I:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMB8J18CAHM3_A/I Tags
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DESD3V3E1BL-7B
Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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Toshiba Semiconductor and Storage
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Diodes Incorporated
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