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Vishay General Semiconductor - Diodes Division SMB8J40CAHM3_B/H
- Part No.:
- SMB8J40CAHM3_B/H
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SMB8J40CAHM3_B/H.pdf
- Description:
- 800W,40V 5%,BIDIR,SMB TVS
- Quantity:
- Payment:
- Shipping:
Inventory:5,067
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Product details
Overview
SMB8J40CAHM3_B/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 40 V stand-off voltage (VWM), 44.4–49.1 V breakdown voltage (VBR), 64.5 V clamping voltage (VC) at 12.4 A peak pulse current (IPPM), and 800 W peak pulse power (PPPM) with 10/1000 µs waveform.
For engineers reviewing the SMB8J40CAHM3_B/H datasheet, SMB8J40CAHM3_B/H pinout, SMB8J40CAHM3_B/H application, or SMB8J40CAHM3_B/H equivalent, this device is selected for automotive-grade ESD/surge protection where AEC-Q101 qualification, low clamping ratio, and halogen-free RoHS compliance are required in sensor interfaces, CAN/LIN bus lines, and DC power rails.
Technical Context
This bidirectional TVS operates symmetrically across both polarities, enabling robust protection against voltage transients induced by inductive switching, ESD, and lightning surges without polarity sensitivity. Its glass-passivated junction ensures stable breakdown characteristics and low incremental surge resistance under repetitive stress.
The device is rated for -55 °C to +150 °C operating junction temperature, meets MSL Level 1 per J-STD-020 (260 °C peak reflow), and delivers 64.5 V clamping at 12.4 A IPPM - critical for maintaining safe voltage margins below IC absolute maximum ratings in automotive and industrial control systems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 40 V - maximum continuous reverse working voltage before leakage exceeds 1.0 µA; defines safe operating margin for 36 V nominal DC rails. |
| VBR min/max | 44.4 V / 49.1 V at 1.0 mA test current - tight breakdown tolerance ensures predictable turn-on during transients. |
| VC @ IPPM | 64.5 V at 12.4 A (10/1000 µs) - clamping voltage directly limits downstream IC stress; clamping ratio = VC/VWM = 1.61. |
| PPPM | 800 W - peak pulse power handling capability determines survivability against IEC 61000-4-5 Level 4 surges (4 kV/2 Ω). |
| RθJL | 20 °C/W - low junction-to-lead thermal resistance enables effective heat dissipation into PCB copper pads during surge events. |
| AEC-Q101 | Qualified - validated for automotive applications including engine control units, ADAS sensors, and body electronics. |
| Package | SMB (DO-214AA) - surface-mount footprint (5.59 mm × 3.94 mm) compatible with automated placement and reflow soldering. |
Pinout & Package
Two-terminal bidirectional device in SMB (DO-214AA) package; no polarity marking on case. Terminals are matte tin-plated leads, solderable per J-STD-002 and JESD 22-B102, with whisker resistance per JESD 201 Class 2.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode/Cathode (symmetrical) | Transient conduction path | Both terminals function identically; bidirectional clamping occurs regardless of voltage polarity applied across the device. |
| Case (cathode band absent) | Non-functional mechanical reference | No electrical connection; absence of color band confirms bidirectional configuration per Vishay marking convention. |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional clamping | Enables single-device protection on AC-coupled or floating signal lines (e.g., CAN differential pairs) without polarity concerns. |
| AEC-Q101 qualification | Validated for automotive underhood and cabin environments, including temperature cycling, humidity bias, and mechanical shock testing. |
| Halogen-free & RoHS-compliant (HM3 suffix) | Meets EU Directive 2011/65/EU and IPC-1752A material declarations; supports green manufacturing and end-of-life recycling. |
| Low clamping ratio (1.61) | Minimizes overvoltage exposure to protected ICs - critical for safeguarding 48 V automotive microcontrollers and transceivers. |
| MSL Level 1 rating | Allows unlimited floor life and standard reflow profile (peak 260 °C), eliminating bake requirements prior to assembly. |
Applications
| Automotive Sensor Interface | CAN Bus Protection |
|---|---|
Use Scenario: Protecting analog output lines of pressure/temperature sensors in engine control modules exposed to load dump and ISO 7637-2 pulses. IC Role / Device Role / Timing Role: Bidirectional TVS clamps transients faster than system response time (<1 ns), preventing latch-up or gate oxide damage in ADC front-end buffers. Use Value: Maintains signal integrity under 40 V nominal supply while surviving 100 V/50 ms load dump events via 64.5 V clamping ceiling. |
Use Scenario: Safeguarding CANH/CANL differential pair in vehicle infotainment gateways against ESD (IEC 61000-4-2 ±15 kV) and burst noise. IC Role / Device Role / Timing Role: Low-capacitance bidirectional clamping prevents data corruption during fast transients without distorting 1 Mbps CAN signaling edges. Use Value: Symmetric clamping preserves common-mode rejection and avoids DC offset shift on differential bus lines. |
| Industrial Power Rail Protection | Telecom DC Feeder Line |
Use Scenario: Guarding 24–48 V DC input rails of PLC I/O modules against inductive kickback from solenoid drivers and relay coils. IC Role / Device Role / Timing Role: Absorbs 800 W surge energy within 1 ms, limiting rail collapse and preventing brownout resets in microcontroller subsystems. Use Value: 12.4 A IPPM rating handles worst-case 500 V/12 Ω surge (per IEC 61000-4-5) without degradation after repeated strikes. |
Use Scenario: Protecting PoE-powered Ethernet switches' 57 V DC feeder inputs from lightning-induced surges on outdoor cabling. IC Role / Device Role / Timing Role: Fast-response TVS diverts surge current away from DC-DC controller ICs before overvoltage shutdown triggers. Use Value: 40 V VWM aligns with IEEE 802.3af/at hold-up voltage, while 64.5 V VC stays below 70 V MOSFET drain-source rating. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMB8J40CAHE3_B/H | Same electrical specs and SMB package; RoHS-compliant but not halogen-free (E3 vs HM3). | Lacks halogen-free certification; acceptable for commercial/industrial use where automotive compliance is not required. | Select when halogen-free material declaration is not mandated by OEM or regulatory requirement. |
| SMAJ40CA | Lower PPPM (400 W), smaller SMA package (DO-214AC), higher RθJA (90 °C/W), same VWM/VC. | Insufficient for 800 W surge events; limited thermal mass reduces reliability in high-repetition surge environments. | Choose only for space-constrained designs with verified lower surge threat levels (e.g., IEC 61000-4-5 Level 2). |
Compared with SMB8J40CAHE3_B/H, the HM3 variant adds halogen-free compliance for automotive Tier 1 supply chains; versus SMAJ40CA, SMB8J40CAHM3_B/H provides double the surge power handling and superior thermal performance in identical PCB layouts.
Availability
SMB8J40CAHM3_B/H is available at Aetrix Electronics and suitable for automotive sensor protection, CAN bus hardening, and industrial 48 V power rail stabilization requiring stable component supply, long-term lifecycle support, and AEC-Q101 traceability.
Supply support for SMB8J40CAHM3_B/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, and protection devices with emphasis on reliability, power density, and automotive qualification.
The SMB8JxxCA series targets high-reliability transient suppression in automotive and industrial systems, engineered specifically for AEC-Q101 compliance, low clamping voltage, and robust surge endurance in compact SMB packages.
FAQ
What is the clamping voltage of SMB8J40CAHM3_B/H at its rated peak pulse current?
The SMB8J40CAHM3_B/H has a maximum clamping voltage (VC) of 64.5 V at 12.4 A peak pulse current (IPPM) using the standard 10/1000 µs waveform. This value is measured under defined test conditions per ANSI/IEEE C62.35 and ensures predictable overvoltage limiting for protected circuitry. The clamping behavior remains consistent across its full operating temperature range (-55 °C to +150 °C).
Is SMB8J40CAHM3_B/H suitable for automotive applications?
Yes, SMB8J40CAHM3_B/H is AEC-Q101 qualified and manufactured with halogen-free, RoHS-compliant materials (HM3 suffix). It meets automotive requirements for temperature cycling, mechanical shock, and surge immunity, making it appropriate for engine control units, ADAS sensors, and body electronics where reliability under harsh conditions is mandatory. The SMB8J40CAHM3_B/H datasheet explicitly lists AEC-Q101 in its mechanical and qualification sections.
How does the bidirectional configuration of SMB8J40CAHM3_B/H affect its use in circuit design?
The bidirectional nature of SMB8J40CAHM3_B/H means it clamps voltage transients equally in both directions, eliminating the need to observe polarity during placement. This simplifies layout for AC-coupled or floating nodes - such as CAN differential pairs or transformer-isolated interfaces - and avoids misapplication risk. Unlike unidirectional TVS diodes, SMB8J40CAHM3_B/H requires no cathode band alignment, and its symmetric VBR/VWM characteristics ensure balanced protection performance.
What is the thermal resistance specification for SMB8J40CAHM3_B/H, and why does it matter?
SMB8J40CAHM3_B/H has a typical junction-to-lead thermal resistance (RθJL) of 20 °C/W, measured with recommended 0.2" × 0.2" copper pads per terminal. This low value enables efficient heat transfer from the silicon junction to the PCB during high-energy transients, reducing thermal stress and improving surge endurance. Compared to alternatives with higher RθJL, SMB8J40CAHM3_B/H sustains repeated 800 W pulses with less junction temperature rise - critical for mission-critical automotive and industrial deployments.
Does SMB8J40CAHM3_B/H meet moisture sensitivity level (MSL) requirements for lead-free reflow?
Yes, SMB8J40CAHM3_B/H meets MSL Level 1 per J-STD-020, with a maximum peak reflow temperature of 260 °C. This allows indefinite floor life and eliminates pre-bake requirements before SMT assembly. The device's construction - including glass-passivated chip junction and matte tin-plated leads - ensures robustness through standard lead-free reflow profiles, supporting high-yield manufacturing for automotive and industrial PCBs.
SMB8J40CAHM3_B/H Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Package/Case:
- DO-214AA, SMB
- Series:
- TransZorb®
- Packaging:
- Bulk
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- -
- Bidirectional Channels:
- 1
- Voltage - Reverse Standoff (Typ):
- 40V
- Voltage - Breakdown (Min):
- 44.4V
- Voltage - Clamping (Max) @ Ipp:
- 64.5V
- Current - Peak Pulse (10/1000µs):
- 12.4A
- 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)
SMB8J40CAHM3_B/H FAQ
1.How can I place an order for SMB8J40CAHM3_B/H through Aetrix?
Please submit a Request for Quotation (RFQ) for SMB8J40CAHM3_B/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 SMB8J40CAHM3_B/H reliable?
The price and inventory of SMB8J40CAHM3_B/H are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMB8J40CAHM3_B/H is usually 5 days.
3.What payment methods are accepted for SMB8J40CAHM3_B/H?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMB8J40CAHM3_B/H transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMB8J40CAHM3_B/H?
SMB8J40CAHM3_B/H orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMB8J40CAHM3_B/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 SMB8J40CAHM3_B/H?
For technical support, including SMB8J40CAHM3_B/H datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMB8J40CAHM3_B/H requirements.
6.How does Aetrix verify that SMB8J40CAHM3_B/H is sourced from the original manufacturer or authorized distributors?
All SMB8J40CAHM3_B/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 SMB8J40CAHM3_B/H meets industry standards.
7.What is the process for return or replacement of SMB8J40CAHM3_B/H?
All SMB8J40CAHM3_B/H units undergo pre-shipment inspection (PSI). If there is an issue with SMB8J40CAHM3_B/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 SMB8J40CAHM3_B/H part is unused and in its original packaging.
Return procedure for SMB8J40CAHM3_B/H:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMB8J40CAHM3_B/H Tags
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