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Vishay General Semiconductor - Diodes Division SMB8J18CAHE3_A/I
- Part No.:
- SMB8J18CAHE3_A/I
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SMB8J18CAHE3_A/I.pdf
- Description:
- TVS DIODE 18VWM 29.2VC DO214AA
- Quantity:
- Payment:
- Shipping:
Inventory:6,828
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Product details
Overview
SMB8J18CAHE3_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 standoff voltage (VWM), 29.2 V clamping voltage (VC) at 27.4 A peak pulse current (IPPM), and 800 W peak pulse power (PPPM) with 10/1000 µs waveform. Used in automotive sensor interfaces and industrial I/O protection where AEC-Q101 qualification and low clamping ratio are critical.
For engineers reviewing the SMB8J18CAHE3_A/I datasheet, SMB8J18CAHE3_A/I pinout, SMB8J18CAHE3_A/I application, or SMB8J18CAHE3_A/I equivalent, this page delivers verified electrical parameters, AEC-Q101 qualification status, bidirectional clamping behavior, thermal resistance (RθJA = 72 °C/W), and automotive-grade packaging details - all confirmed from Vishay's official document 88422 (Rev. 09-Jan-2024).
Technical Context
This device operates as a voltage-clamped crowbar during transients: when reverse voltage exceeds its breakdown range (20.0–22.1 V at 1 mA), it avalanches to limit downstream voltage to ≤29.2 V under 27.4 A surge. Its glass-passivated junction ensures stable leakage (<1.0 µA at 18 V) and fast response (<1 ns), meeting ANSI/IEEE C62.35 standards for surge immunity.
Designed for surface-mount automated assembly, it uses matte tin-plated leads compliant with J-STD-002 and JESD 22-B102, and achieves MSL Level 1 per J-STD-020 with 260 °C reflow peak. The SMB (DO-214AA) case provides UL 94 V-0 flammability rating and supports 0.2" × 0.2" copper pad layout for optimal thermal dissipation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 18 V - maximum continuous reverse operating voltage before clamping begins; defines safe signal line bias margin |
| VBR (min/max) | 20.0 V / 22.1 V at 1 mA - precise avalanche initiation window ensuring consistent turn-on across temperature and unit variation |
| VC @ IPPM | 29.2 V at 27.4 A - clamping voltage under 10/1000 µs surge; determines protected circuit's maximum transient exposure |
| PPPM | 800 W - peak pulse power handling capacity; enables robust protection against IEC 61000-4-5 Level 4 surges |
| ID @ VWM | <1.0 µA - ultra-low reverse leakage preserves signal integrity and minimizes standby power loss |
| RθJA | 72 °C/W - junction-to-ambient thermal resistance; informs board-level copper pad sizing and derating above 25 °C |
| AEC-Q101 | Qualified - validated for automotive applications including engine control, ADAS sensors, and infotainment I/O |
Pinout & Package
Package: SMB (DO-214AA), surface-mount, bidirectional configuration with no polarity marking (unlike unidirectional variants which use cathode band). Dimensions: 4.57 mm × 3.94 mm × 2.20 mm (L × W × H); weight: 0.106 g.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Transient return path (bidirectional) | Acts as cathode during positive transients and anode during negative transients; symmetric conduction enables dual-polarity clamping |
| Cathode | Transient return path (bidirectional) | Electrically identical to Anode in bidirectional construction; terminals are interchangeable with no marking required |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive-grade reliability including temperature cycling, humidity testing, and mechanical shock per AEC specification |
| Glass passivated junction | Ensures stable VBR over lifetime and immunity to moisture-induced parameter drift in harsh environments |
| Low clamping ratio (VC/VBR ≈ 1.39) | Minimizes overvoltage stress on protected ICs - critical for 3.3 V/5 V logic and automotive CAN/LIN transceivers |
| MSL Level 1, 260 °C peak | Enables standard lead-free reflow without pre-baking; compatible with high-volume SMT production lines |
| UL 94 V-0 molding compound | Provides flame-retardant housing essential for automotive cabin and industrial control enclosure compliance |
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 ESD in vehicle body control modules. IC Role / Device Role / Timing Role: Bidirectional voltage clamp placed between sensor output and microcontroller ADC input or LIN driver. Use Value: Limits transient excursions to ≤29.2 V while maintaining <1.0 µA leakage at 18 V, preserving signal fidelity and enabling direct connection to 3.3 V rail-tied inputs. |
Use Scenario: Safeguarding PLC digital input channels exposed to inductive switching noise from solenoids and relays in factory automation cabinets. IC Role / Device Role / Timing Role: Parallel-connected TVS on 24 V DC input lines upstream of optocoupler or Schmitt trigger interface. Use Value: Absorbs 800 W surges without degradation, with RθJA = 72 °C/W allowing operation up to +85 °C ambient when mounted on 5 mm × 5 mm copper pads. |
| Automotive Infotainment USB Port | Telecom Line Card Surge Protection |
Use Scenario: Shielding USB 2.0 D+/D− lines in head unit applications from ESD events and coupled transients during ignition switching. IC Role / Device Role / Timing Role: Low-capacitance bidirectional TVS placed directly at USB connector, before ESD protection IC or PHY. Use Value: Clamps ±15 kV contact ESD (IEC 61000-4-2) within nanoseconds while adding negligible capacitance to high-speed data paths. |
Use Scenario: Front-end protection for Ethernet PHYs and analog telephone line interfaces subjected to lightning-induced surges per IEC 61000-4-5. IC Role / Device Role / Timing Role: Primary surge suppression stage on twisted-pair telecom lines before isolation transformer and receiver IC. Use Value: Handles 27.4 A peak current (10/1000 µs) with 29.2 V clamping, reducing secondary protection burden and enabling compact line card designs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ18CAHE3_A/I | Same SMB package and 18 V VWM, but rated for 1000 W PPPM (unidirectional only); bidirectional variant SMBJ18CA has lower 600 W rating | Higher power rating suits single-polarity rails; not AEC-Q101 qualified in HE3 suffix unless explicitly marked | Select SMB8J18CAHE3_A/I when AEC-Q101 compliance and 800 W bidirectional capability are mandatory |
| SMCJ18CAHE3_A/I | Larger SMC (DO-214AB) package with 1500 W PPPM; identical VWM and VC but higher thermal mass (RθJA = 35 °C/W) | Better suited for high-repetition surges or elevated ambient temperatures; requires larger PCB footprint | Choose SMB8J18CAHE3_A/I for space-constrained automotive modules where SMB footprint and AEC-Q101 are prioritized over peak power headroom |
Compared with SMBJ18CAHE3_A/I and SMCJ18CAHE3_A/I, SMB8J18CAHE3_A/I uniquely balances AEC-Q101 qualification, 800 W bidirectional surge capability, and minimal SMB footprint - making it optimal for automotive sensor nodes and compact industrial I/O where regulatory compliance and board area are co-constrained.
Availability
SMB8J18CAHE3_A/I is available at Aetrix Electronics and suitable for automotive sensor interfaces, industrial digital I/O protection, and telecom line card surge suppression requiring stable component supply, full traceability, and long-term lifecycle support.
Supply support for SMB8J18CAHE3_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, MOSFETs, optoelectronics, and passive components with emphasis on reliability and application-specific performance.
The SMB8J series belongs to Vishay's TRANSZORB® TVS family, engineered specifically for high-power-density, AEC-Q101-compliant transient suppression in automotive and industrial environments where clamping precision and thermal robustness are critical.
FAQ
What is the clamping voltage of SMB8J18CAHE3_A/I under maximum surge conditions?
The SMB8J18CAHE3_A/I exhibits a maximum clamping voltage (VC) of 29.2 V when subjected to its rated peak pulse current of 27.4 A using the standardized 10/1000 µs waveform. This value is measured at TA = 25 °C with recommended 0.2" × 0.2" copper pads and is guaranteed across the full operating temperature range of −55 °C to +150 °C. The SMB8J18CAHE3_A/I maintains this clamping performance consistently due to its glass-passivated junction structure.
Is SMB8J18CAHE3_A/I suitable for automotive applications?
Yes, SMB8J18CAHE3_A/I is explicitly AEC-Q101 qualified per Vishay document 88422, making it suitable for automotive applications including body electronics, ADAS sensor interfaces, and infotainment systems. Its construction meets automotive requirements for thermal cycling, humidity resistance, and mechanical shock. The HE3 suffix confirms RoHS compliance and AEC-Q101 qualification, and the SMB (DO-214AA) package supports automated placement in Tier 1 manufacturing lines.
How does SMB8J18CAHE3_A/I differ from unidirectional TVS diodes like SMB10J18AHE3_A/I?
SMB8J18CAHE3_A/I is bidirectional, meaning it clamps voltage transients of either polarity symmetrically - essential for AC-coupled or differential signal lines such as LIN, CAN, or telecom pairs. In contrast, SMB10J18AHE3_A/I is unidirectional with a cathode band marking and only protects against reverse-polarity surges. SMB8J18CAHE3_A/I has a lower peak pulse power rating (800 W vs. 1000 W) but identical VWM (18 V) and comparable clamping voltage (29.2 V vs. 29.2 V), with both sharing AEC-Q101 qualification in HE3 suffix variants.
What is the thermal resistance of SMB8J18CAHE3_A/I, and how does it affect PCB layout?
The SMB8J18CAHE3_A/I has a typical junction-to-ambient thermal resistance (RθJA) of 72 °C/W when mounted on 0.2" × 0.2" (5.0 mm × 5.0 mm) copper pads per terminal. This value directly dictates minimum copper area needed to maintain junction temperature below 150 °C under repeated surge conditions. For continuous operation near maximum ratings, designers must allocate adequate thermal relief - e.g., internal ground planes or thermal vias - since exceeding thermal limits degrades clamping consistency and long-term reliability of the SMB8J18CAHE3_A/I.
Does SMB8J18CAHE3_A/I require polarity orientation during PCB placement?
No, SMB8J18CAHE3_A/I does not require polarity orientation because it is a bidirectional TVS diode. Unlike unidirectional variants (e.g., SMB10J18AHE3_A/I) that feature a visible cathode band, the SMB8J18CAHE3_A/I has no marking and functions identically regardless of terminal orientation. This simplifies automated placement and eliminates risk of reverse installation - a key advantage in high-density automotive PCBs where space and assembly yield are critical for the SMB8J18CAHE3_A/I.
SMB8J18CAHE3_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:
- -
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AA (SMB)
SMB8J18CAHE3_A/I FAQ
1.How can I place an order for SMB8J18CAHE3_A/I through Aetrix?
Please submit a Request for Quotation (RFQ) for SMB8J18CAHE3_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 SMB8J18CAHE3_A/I reliable?
The price and inventory of SMB8J18CAHE3_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 SMB8J18CAHE3_A/I is usually 5 days.
3.What payment methods are accepted for SMB8J18CAHE3_A/I?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMB8J18CAHE3_A/I transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMB8J18CAHE3_A/I?
SMB8J18CAHE3_A/I orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMB8J18CAHE3_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 SMB8J18CAHE3_A/I?
For technical support, including SMB8J18CAHE3_A/I datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMB8J18CAHE3_A/I requirements.
6.How does Aetrix verify that SMB8J18CAHE3_A/I is sourced from the original manufacturer or authorized distributors?
All SMB8J18CAHE3_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 SMB8J18CAHE3_A/I meets industry standards.
7.What is the process for return or replacement of SMB8J18CAHE3_A/I?
All SMB8J18CAHE3_A/I units undergo pre-shipment inspection (PSI). If there is an issue with SMB8J18CAHE3_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 SMB8J18CAHE3_A/I part is unused and in its original packaging.
Return procedure for SMB8J18CAHE3_A/I:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMB8J18CAHE3_A/I Tags
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