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Vishay General Semiconductor - Diodes Division SMB8J18CAHM3_A/H
- Part No.:
- SMB8J18CAHM3_A/H
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SMB8J18CAHM3_A/H.pdf
- Description:
- TVS DIODE 18VWM 29.2VC DO214AA
- Quantity:
- Payment:
- Shipping:
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Product details
Overview
SMB8J18CAHM3_A/H 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), 800 W peak pulse power (10/1000 µs), and AEC-Q101 qualification for automotive use.
For engineers reviewing the SMB8J18CAHM3_A/H datasheet, SMB8J18CAHM3_A/H pinout, SMB8J18CAHM3_A/H application, or SMB8J18CAHM3_A/H equivalent, key selection criteria include bidirectional clamping behavior, low clamping ratio (VC/VWM = 1.62), MSL Level 1 moisture sensitivity, halogen-free RoHS compliance, and suitability for CAN bus, sensor I/O, and 12 V automotive power rail protection.
Technical Context
This device operates as a voltage-clamped surge protector with symmetrical breakdown in both polarities, enabling robust protection against ESD, load dump, and inductive switching transients without polarity constraints. Its glass-passivated junction ensures stable leakage (<1.0 µA at VWM) and fast response time (<1 ns), while the low incremental surge resistance supports consistent clamping under repetitive surges.
The SMB8J18CAHM3_A/H is rated for TJ = –55 °C to +150 °C and exhibits RθJA = 72 °C/W and RθJL = 20 °C/W thermal resistance, confirming its suitability for surface-mount applications with minimal copper pad area (0.2" × 0.2"). It meets ANSI/IEEE C62.35 standards and is qualified per AEC-Q101 for automotive underhood and body electronics.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 18 V - Maximum continuous reverse operating voltage before clamping begins; defines safe operating margin for 12 V nominal systems. |
| VBR (min/max) | 20.0 V / 22.1 V - Breakdown occurs within this range at 1.0 mA test current; ensures predictable turn-on threshold across temperature and lot variation. |
| VC @ IPPM | 29.2 V - Clamps transients to ≤29.2 V at 27.4 A (10/1000 µs), limiting downstream IC stress during ISO 7637-2 Pulse 1/2a/5a events. |
| PPPM | 800 W - Sustains 800 W peak pulse power for standard 10/1000 µs waveform; enables protection of medium-power interfaces like LIN or analog sensor inputs. |
| IPPM | 27.4 A - Peak surge current capability at VC; sufficient for automotive load-dump suppression per ISO 16750-2. |
| TJ max | +150 °C - Junction temperature rating supports under-hood placement in engine control units and body controllers. |
| Leakage @ VWM | ≤1.0 µA - Ultra-low reverse leakage preserves signal integrity and battery life in always-on circuits. |
Pinout & Package
Package: SMB (DO-214AA), surface-mount, halogen-free, RoHS-compliant, AEC-Q101 qualified. Dimensions: 4.57 mm × 3.94 mm × 2.20 mm (L × W × H); matte tin-plated leads, solderable per J-STD-002/JESD 22-B102.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (unmarked end) | Low-side terminal in bidirectional operation | Acts as cathode during positive transients and anode during negative transients; no polarity marking required for bidirectional types. |
| Cathode (unmarked end) | High-side terminal in bidirectional operation | Functions identically to anode under reverse polarity; symmetrical conduction enables single-device protection of AC or floating lines. |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional clamping | Enables single-device protection of differential, AC-coupled, or floating signal lines without external polarity management. |
| AEC-Q101 qualification | Validated for automotive-grade reliability including temperature cycling, humidity bias, and mechanical shock per stress test requirements. |
| MSL Level 1 (260 °C peak) | Supports standard lead-free reflow without baking or special handling, reducing manufacturing complexity and cost. |
| Glass-passivated junction | Ensures long-term stability of VBR and leakage under thermal aging and humidity exposure in harsh environments. |
| Low clamping ratio (VC/VWM = 1.62) | Minimizes overvoltage stress on protected ICs compared to higher-ratio TVS devices, improving system-level surge margin. |
Applications
| Automotive Sensor Interface | CAN Bus Physical Layer |
|---|---|
Use Scenario: Protecting analog outputs of pressure, temperature, or position sensors connected to MCU ADC inputs in engine control modules. IC Role / Device Role / Timing Role: Bidirectional voltage clamp placed between sensor output and MCU input pin to shunt ESD and cable-induced transients. Use Value: Limits transient voltage to ≤29.2 V while maintaining <1.0 µA leakage, preserving ADC accuracy and preventing latch-up in 3.3 V/5 V MCUs. | Use Scenario: Safeguarding CANH/CANL lines in automotive body control modules against ISO 7637-2 coupled surges and ESD events. IC Role / Device Role / Timing Role: Differential TVS pair (two SMB8J18CAHM3_A/H) placed across CANH–CANL to clamp common-mode transients without disrupting DC bias. Use Value: Withstands 800 W pulses and clamps to 29.2 V, ensuring CAN transceivers remain operational during 12 V system load dump events. |
| Industrial PLC Analog Input | 12 V Power Rail Protection |
Use Scenario: Shielding 4–20 mA current loop inputs in programmable logic controllers from field wiring transients and ground bounce. IC Role / Device Role / Timing Role: Bidirectional TVS installed between input terminals and ground to absorb induced surges without polarity dependence. Use Value: Symmetrical clamping eliminates need for dual unidirectional devices, simplifying BOM and PCB layout while meeting IEC 61000-4-5 Level 3 requirements. | Use Scenario: Guarding 12 V supply rails feeding infotainment head units or ADAS camera modules against battery line transients. IC Role / Device Role / Timing Role: TVS placed between VIN and GND to clamp load dump spikes up to 27.4 A (10/1000 µs) before LDO or DC/DC input stage. Use Value: 800 W rating and 29.2 V clamping prevent overvoltage damage to downstream regulators, extending system uptime in stop-start vehicle architectures. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMB8J18CAHE3_A/H | RoHS-compliant but not halogen-free; same electrical specs and AEC-Q101 qualification. | Acceptable for commercial automotive modules where halogen-free material is not mandated by OEM spec. | Select when cost optimization is prioritized and halogen-free certification is not required. |
| SMAJ18CA | Lower PPPM (400 W), smaller SMA package (DO-214AC), higher VC (29.8 V), same VWM and VBR. | Suitable for space-constrained consumer or industrial designs where 800 W surge capacity is not needed. | Choose for compact layouts with lower surge exposure; avoid for under-hood automotive use requiring full AEC-Q101 and 800 W rating. |
Compared with SMB8J18CAHE3_A/H, the SMB8J18CAHM3_A/H adds halogen-free compliance without sacrificing performance; versus SMAJ18CA, it delivers double the surge power in a slightly larger but thermally superior SMB package-critical for sustained transient immunity in automotive power domains.
Availability
SMB8J18CAHM3_A/H is available at Aetrix Electronics and suitable for automotive sensor protection, CAN bus safeguarding, industrial analog input conditioning, and 12 V power rail surge suppression requiring stable component supply across production lifecycles.
Supply support for SMB8J18CAHM3_A/H 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 automotive-grade qualification.
The SMB8J18CAHM3_A/H belongs to Vishay's TRANSZORB® family of high-power-density TVS diodes, engineered specifically for robust transient suppression in automotive, industrial, and transportation systems exposed to severe electrical stress.
FAQ
What is the clamping voltage of SMB8J18CAHM3_A/H at its rated peak pulse current?
The SMB8J18CAHM3_A/H has a maximum clamping voltage (VC) of 29.2 V when subjected to its rated peak pulse current (IPPM) of 27.4 A under the standard 10/1000 µs waveform. This value is measured per ANSI/IEEE C62.35 and confirmed in Vishay's Document Number 88422, ensuring predictable overvoltage limiting for protected circuitry.
Is SMB8J18CAHM3_A/H suitable for automotive applications?
Yes, SMB8J18CAHM3_A/H is AEC-Q101 qualified and explicitly designated for automotive use with suffix "HM3" indicating halogen-free, RoHS-compliant, and automotive-grade construction. It meets requirements for under-hood and body electronics, including resistance to thermal cycling, humidity bias, and mechanical shock per AEC-Q101 stress tests.
What does the "HM3" suffix mean in SMB8J18CAHM3_A/H?
The "HM3" suffix in SMB8J18CAHM3_A/H denotes halogen-free, RoHS-compliant, and AEC-Q101 qualified construction. It distinguishes this variant from commercial-grade "E3" or "M3" versions and confirms compliance with automotive material restrictions and reliability standards defined in the Vishay ordering nomenclature.
How does SMB8J18CAHM3_A/H differ from unidirectional TVS diodes like SMB10J18A?
SMB8J18CAHM3_A/H is bidirectional with symmetrical breakdown and clamping in both polarities, making it ideal for AC, differential, or floating lines. In contrast, SMB10J18A is unidirectional, conducts only in reverse bias, and requires correct polarity orientation-limiting its use to DC-biased single-ended signals where cathode/anode placement is controlled.
What is the maximum operating junction temperature for SMB8J18CAHM3_A/H?
The SMB8J18CAHM3_A/H has a maximum operating junction temperature (TJ) of +150 °C, as specified in Vishay's Document Number 88422. This rating supports reliable operation in high-temperature automotive environments such as engine compartments, transmission control units, and power distribution modules.
SMB8J18CAHM3_A/H 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/H FAQ
1.How can I place an order for SMB8J18CAHM3_A/H through Aetrix?
Please submit a Request for Quotation (RFQ) for SMB8J18CAHM3_A/H 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/H reliable?
The price and inventory of SMB8J18CAHM3_A/H 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/H is usually 5 days.
3.What payment methods are accepted for SMB8J18CAHM3_A/H?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMB8J18CAHM3_A/H transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMB8J18CAHM3_A/H?
SMB8J18CAHM3_A/H orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMB8J18CAHM3_A/H 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/H?
For technical support, including SMB8J18CAHM3_A/H datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMB8J18CAHM3_A/H requirements.
6.How does Aetrix verify that SMB8J18CAHM3_A/H is sourced from the original manufacturer or authorized distributors?
All SMB8J18CAHM3_A/H 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/H meets industry standards.
7.What is the process for return or replacement of SMB8J18CAHM3_A/H?
All SMB8J18CAHM3_A/H units undergo pre-shipment inspection (PSI). If there is an issue with SMB8J18CAHM3_A/H, 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/H part is unused and in its original packaging.
Return procedure for SMB8J18CAHM3_A/H:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMB8J18CAHM3_A/H Tags
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