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Vishay General Semiconductor - Diodes Division SMB8J18CAHM3_B/I
- Part No.:
- SMB8J18CAHM3_B/I
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SMB8J18CAHM3_B/I.pdf
- Description:
- 800W,18V 5%,BIDIR,SMB TVS
- Quantity:
- Payment:
- Shipping:
Inventory:9,054
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Product details
Overview
SMB8J18CAHM3_B/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_B/I datasheet, SMB8J18CAHM3_B/I pinout, SMB8J18CAHM3_B/I application, or SMB8J18CAHM3_B/I equivalent, key selection criteria include bidirectional clamping capability, AEC-Q101 qualification, low clamping ratio (VC/VWM ≈ 1.62), and compatibility with automated SMT assembly on 5.0 mm × 5.0 mm copper pads.
Technical Context
This device operates as a voltage-clamped crowbar during transients, leveraging an avalanche breakdown junction to divert surge energy away from downstream ICs. Its bidirectional symmetry enables protection of AC-coupled or differential signal paths without polarity constraints.
Thermal performance is defined by RθJA = 72 °C/W and RθJL = 20 °C/W, supporting operation up to +150 °C junction temperature. It meets J-STD-020 MSL Level 1 and passes JESD201 Class 2 whisker testing with matte tin-plated leads.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 18 V - maximum continuous reverse operating voltage before clamping begins; sets safe operating margin for 12–15 V nominal systems. |
| VBR min/max | 20.0 V / 22.1 V at 1.0 mA - verified breakdown threshold ensures consistent turn-on across production lots. |
| VC @ IPPM | 29.2 V at 27.4 A - clamping voltage limits stress on protected circuitry during 10/1000 µs surges. |
| PPPM | 800 W - peak power handling capacity under standardized lightning-surge waveform (IEC 61000-4-5). |
| ID @ VWM | 1.0 µA - ultra-low leakage preserves signal integrity and battery life in always-on circuits. |
| TJ max | +150 °C - supports under-hood automotive environments and high-temperature industrial enclosures. |
| AEC-Q101 | Qualified - validated for automotive-grade reliability including temperature cycling, HTRB, and ESD robustness. |
Pinout & Package
Package: SMB (DO-214AA), surface-mount, halogen-free, RoHS-compliant, with matte tin-plated leads solderable per J-STD-002 and JESD22-B102. No polarity marking - bidirectional construction eliminates cathode/anode orientation concerns during placement.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode/Cathode (symmetrical) | Transient conduction path | Both terminals function identically; surge current flows bidirectionally through the same junction structure. |
| Cathode Band (absent) | Polarity indicator | Not applicable - bidirectional devices omit band marking per Vishay mechanical specification. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive electronics including engine control units, ADAS sensors, and body controllers. |
| Low clamping ratio (VC/VWM = 1.62) | Minimizes overvoltage exposure to protected ICs compared to higher-ratio TVS devices. |
| MSL Level 1 rating | Enables direct placement without baking; compatible with standard reflow profiles up to 260 °C peak. |
| Halogen-free & RoHS-compliant (HM3 suffix) | Meets EU environmental directives and automotive material compliance requirements (e.g., GMW3172). |
| 800 W peak pulse power | Withstands IEC 61000-4-5 Level 4 (4 kV/2 Ω) surges on 12 V supply rails without degradation. |
Applications
| Automotive Sensor Interface | Industrial Digital I/O Protection |
|---|---|
Use Scenario: Protecting LIN bus transceivers and analog sensor outputs (e.g., pressure, temperature) from load dump and ISO 7637-2 pulses. IC Role / Device Role / Timing Role: Bidirectional voltage clamp placed between sensor output and microcontroller ADC input or LIN transceiver pin. Use Value: Limits transient voltage to ≤29.2 V while maintaining <1.0 µA leakage - preserving measurement accuracy and preventing MCU reset. |
Use Scenario: Safeguarding PLC digital input modules against field-wiring induced surges and ground loop transients. IC Role / Device Role / Timing Role: Primary surge suppression element on 24 V DC input channels prior to optocoupler or Schmitt trigger conditioning. Use Value: Absorbs 800 W surges without failure, enabling >100,000 surge cycles per IEC 61000-4-5 compliance testing. |
| Automotive Body Control Module | Consumer Appliance Motor Drive Interface |
Use Scenario: Shielding CAN FD transceiver power rails and wake-up lines from battery line transients during ignition and alternator load dump. IC Role / Device Role / Timing Role: Secondary protection stage after primary fuse and upstream TVS, placed directly at transceiver VCC pin. Use Value: AEC-Q101 qualification ensures zero infant mortality in 15-year vehicle service life; 150 °C TJ rating supports under-dash mounting. |
Use Scenario: Protecting microcontroller GPIOs connected to brushed DC motor feedback lines subject to back-EMF spikes. IC Role / Device Role / Timing Role: Fast-response shunt device across motor sense resistor or hall-effect sensor supply. Use Value: 10/1000 µs response delivers clamping within 1 ns - faster than MOSFET body diodes - preventing latch-up in 3.3 V logic. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMB8J18CAHE3_B/I | Same electrical specs; RoHS-compliant but not halogen-free; lacks HM3 material certification. | Acceptable for commercial/industrial use where halogen-free requirement is absent. | Select when cost sensitivity outweighs automotive material compliance needs. |
| SMAJ18CA-M3/5B | Lower PPPM (400 W), smaller SMA package (DO-214AC), higher RθJA (90 °C/W). | Suitable only for lower-energy surges (<2 kV) and space-constrained PCBs with thermal derating. | Choose only if board area is critical and surge threat level is below IEC 61000-4-5 Level 2. |
Compared with SMB8J18CAHE3_B/I, the SMB8J18CAHM3_B/I adds halogen-free compliance for automotive Tier 1 sourcing; versus SMAJ18CA-M3/5B, it delivers double the surge power handling and superior thermal dissipation in the same footprint class.
Availability
SMB8J18CAHM3_B/I is available at Aetrix Electronics and suitable for automotive sensor protection, industrial PLC I/O hardening, and consumer appliance motor interface designs requiring stable component supply and long-term lifecycle support.
Supply support for SMB8J18CAHM3_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 high-reliability diodes, MOSFETs, and passive components for automotive, industrial, and computing markets.
The SMB8JxxCA series targets AEC-Q101-compliant transient suppression in harsh-environment electronics, emphasizing robust clamping, low leakage, and automated manufacturability.
FAQ
What is the clamping voltage of SMB8J18CAHM3_B/I at its rated peak pulse current?
The SMB8J18CAHM3_B/I has a maximum clamping voltage (VC) of 29.2 V when subjected to its rated peak pulse current (IPPM) of 27.4 A under a 10/1000 µs waveform. This value is measured per ANSI/IEEE C62.35 and guarantees predictable overvoltage limiting for protected circuits - a critical parameter for safeguarding 3.3 V or 5 V microcontrollers interfacing with 12 V automotive domains. The SMB8J18CAHM3_B/I maintains this clamping performance across its full operating temperature range.
Is SMB8J18CAHM3_B/I suitable for automotive applications?
Yes, SMB8J18CAHM3_B/I is AEC-Q101 qualified and manufactured with halogen-free, RoHS-compliant materials (HM3 suffix), making it approved for automotive use in engine control, body electronics, and ADAS subsystems. Its 150 °C maximum junction temperature, MSL Level 1 rating, and JESD201 Class 2 whisker resistance meet stringent automotive reliability standards. The SMB8J18CAHM3_B/I is explicitly listed in Vishay's AEC-Q101 qualified product matrix for transient suppression.
How does SMB8J18CAHM3_B/I differ from unidirectional variants like SMB10J18A?
The SMB8J18CAHM3_B/I is bidirectional with symmetrical clamping in both polarities, whereas SMB10J18A is unidirectional and conducts only in reverse bias. SMB8J18CAHM3_B/I offers 800 W PPPM and 27.4 A IPPM, while SMB10J18A delivers 1000 W PPPM and 34.2 A IPPM but requires correct polarity orientation. The SMB8J18CAHM3_B/I eliminates layout errors from misoriented placement - critical in differential or AC-coupled signal paths where polarity is undefined.
What is the thermal resistance of SMB8J18CAHM3_B/I, and how does it affect PCB layout?
SMB8J18CAHM3_B/I has a typical junction-to-ambient thermal resistance (RθJA) of 72 °C/W and junction-to-lead (RθJL) of 20 °C/W. To achieve rated power dissipation, Vishay specifies mounting on 0.2" × 0.2" (5.0 mm × 5.0 mm) copper pads per terminal. Reducing pad size or omitting thermal vias increases junction temperature - potentially derating PPPM by >20% at 85 °C ambient. The SMB8J18CAHM3_B/I datasheet provides derating curves (Fig. 2) for precise thermal design.
Does SMB8J18CAHM3_B/I require special handling or moisture sensitivity precautions?
No - SMB8J18CAHM3_B/I is rated MSL Level 1 per J-STD-020, meaning it may be stored indefinitely at ≤30 °C/85% RH and processed using standard SMT reflow profiles without pre-baking. Its matte tin-plated leads comply with J-STD-002 for solderability, and the molding compound meets UL 94 V-0 flammability. These attributes make SMB8J18CAHM3_B/I ideal for high-volume automated assembly without process modifications.
SMB8J18CAHM3_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:
- 18V
- 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_B/I FAQ
1.How can I place an order for SMB8J18CAHM3_B/I through Aetrix?
Please submit a Request for Quotation (RFQ) for SMB8J18CAHM3_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 SMB8J18CAHM3_B/I reliable?
The price and inventory of SMB8J18CAHM3_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 SMB8J18CAHM3_B/I is usually 5 days.
3.What payment methods are accepted for SMB8J18CAHM3_B/I?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMB8J18CAHM3_B/I transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMB8J18CAHM3_B/I?
SMB8J18CAHM3_B/I orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMB8J18CAHM3_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 SMB8J18CAHM3_B/I?
For technical support, including SMB8J18CAHM3_B/I datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMB8J18CAHM3_B/I requirements.
6.How does Aetrix verify that SMB8J18CAHM3_B/I is sourced from the original manufacturer or authorized distributors?
All SMB8J18CAHM3_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 SMB8J18CAHM3_B/I meets industry standards.
7.What is the process for return or replacement of SMB8J18CAHM3_B/I?
All SMB8J18CAHM3_B/I units undergo pre-shipment inspection (PSI). If there is an issue with SMB8J18CAHM3_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 SMB8J18CAHM3_B/I part is unused and in its original packaging.
Return procedure for SMB8J18CAHM3_B/I:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMB8J18CAHM3_B/I Tags
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