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Vishay General Semiconductor - Diodes Division SMB8J40CAHM3/H
- Part No.:
- SMB8J40CAHM3/H
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SMB8J40CAHM3/H.pdf
- Description:
- TVS DIODE 40VWM 64.5VC DO214AA
- Quantity:
- Payment:
- Shipping:
Inventory:3,302
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Product details
Overview
SMB8J40CAHM3/H from Vishay General Semiconductor is a bidirectional transient voltage suppressor (TVS) diode in SMB (DO-214AA) package, designed for high-energy surge protection with 800 W peak pulse power (10/1000 μs), 40 V stand-off voltage (VWM), and 64.5 V clamping voltage (VC) at 12.4 A peak pulse current. It is AEC-Q101 qualified and used to protect automotive sensor signal lines, power supply inputs, and CAN/LIN bus interfaces against ESD and load dump transients.
For engineers reviewing the SMB8J40CAHM3/H datasheet, SMB8J40CAHM3/H pinout, SMB8J40CAHM3/H application, or SMB8J40CAHM3/H equivalent, this page delivers verified electrical specs, automotive-grade qualification status, thermal resistance data, clamping behavior under surge, and real-world protection use cases - all confirmed from Vishay's official 88422 document (Rev. 09-Jan-2024).
Technical Context
This bidirectional TVS operates symmetrically across both polarities, enabling robust protection of AC-coupled or differential signal paths without polarity constraints. Its glass-passivated junction ensures stable breakdown characteristics and low leakage (<1.0 μA at VWM), while the low incremental surge resistance supports fast clamping response under 1 ns.
The device is rated for TJ = -55 °C to +150 °C operation and features RθJA = 72 °C/W (typical) and RθJL = 20 °C/W (typical), confirming suitability for thermally constrained PCB layouts with minimal copper pad area (0.2" × 0.2"). It meets MSL Level 1 per J-STD-020 and is halogen-free, RoHS-compliant, and AEC-Q101 qualified (HM3 suffix).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 40 V - maximum continuous reverse operating voltage before clamping begins; defines safe signal swing range for protected circuitry |
| VBR (min/max) | 44.4 V / 49.1 V - breakdown occurs within this band at 1.0 mA test current; ensures predictable turn-on threshold |
| VC @ IPPM | 64.5 V at 12.4 A - clamping voltage during 10/1000 μs surge; limits voltage seen by downstream ICs to safe level |
| PPPM | 800 W - peak pulse power handling capability; determines survivability against ISO 7637-2 Pulse 1/2/5a surges |
| ID @ VWM | ≤1.0 μA - ultra-low reverse leakage at stand-off voltage; avoids signal distortion or bias shift in high-impedance nodes |
| TJ max. | +150 °C - maximum junction temperature rating; enables use in under-hood automotive environments |
| RθJA | 72 °C/W - thermal resistance junction-to-ambient on standard 0.2" × 0.2" pads; informs derating requirements above 25 °C ambient |
Pinout & Package
Package: SMB (DO-214AA), surface-mount, bidirectional configuration with no polarity marking - symmetrical terminals suitable for AC or differential line protection.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode/Cathode (symmetrical) | Transient conduction path | Both terminals function identically; conducts surge current bidirectionally when voltage exceeds ±VBR |
| Cathode Band (absent) | Polarity indicator | Not present on bidirectional variants - confirms no DC bias dependency in protected path |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualification | Validated for automotive applications including engine control, body electronics, and ADAS sensor interfaces |
| Halogen-free & RoHS-compliant (HM3) | Meets automotive environmental compliance standards and JESD201 Class 2 whisker resistance |
| Low-profile SMB package | Enables automated placement and fits tight board spaces typical in ECU and module-level designs |
| 800 W peak pulse power (10/1000 μs) | Withstands ISO 7637-2 Pulse 5a (load dump) up to 12.4 A without failure |
| Fast response time & low clamping ratio | Clamps within nanoseconds with VC/VBR ≈ 1.45 - minimizes overvoltage stress on protected ICs |
Applications
| Automotive Sensor Signal Protection | CAN Bus Transient Suppression |
|---|---|
Use Scenario: Protecting analog output lines of pressure, temperature, or position sensors in engine bay modules exposed to load dump and ISO 10605 ESD. IC Role / Device Role / Timing Role: Bidirectional voltage clamp placed directly at connector entry point to shunt transients before reaching ADC input or signal conditioner. Use Value: Limits voltage excursion to ≤64.5 V during 10/1000 μs surges, preserving sensor accuracy and preventing microcontroller reset or latch-up. | Use Scenario: Safeguarding CANH/CANL differential pair in automotive gateways or ECUs against coupled transients from adjacent power circuits. IC Role / Device Role / Timing Role: Low-capacitance bidirectional TVS installed across CAN bus lines to absorb common-mode surges without distorting signal integrity. Use Value: Maintains <1.0 μA leakage at 40 V stand-off, avoiding bus bias shift; clamps to 64.5 V before CAN transceiver damage threshold is exceeded. |
| Industrial PLC I/O Protection | Power Supply Input Clamping |
Use Scenario: Shielding digital and analog I/O channels of programmable logic controllers from field-induced surges in factory automation environments. IC Role / Device Role / Timing Role: Primary surge suppression element on terminal block side of isolation barrier, upstream of optocouplers or signal conditioners. Use Value: Withstands repeated 800 W pulses per IEC 61000-4-5 Level 3 (2 kV), ensuring long-term reliability without parameter drift. | Use Scenario: Protecting 24 V DC input rails of industrial HMIs and motor drives from inductive switching spikes and lightning-induced surges. IC Role / Device Role / Timing Role: Parallel-connected TVS at power entry point, sized to clamp 40 V nominal rail to ≤64.5 V during transient events. Use Value: Delivers 800 W surge handling with RθJL = 20 °C/W - enables direct mounting to ground plane for efficient heat dissipation during sustained overvoltage. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMB8J40CAHE3/H | Same electrical specs and package; RoHS-compliant but not halogen-free; lacks JESD201 Class 2 whisker rating | Approved for commercial and industrial use; not certified for automotive under hood | Select when halogen-free requirement or AEC-Q101 qualification is not mandated |
| SMAJ40CA | Lower PPPM (400 W), higher RθJA (90 °C/W), SMA package (smaller footprint, lower surge capacity) | Suitable only for lighter-duty protection; insufficient for ISO 7637-2 Pulse 5a | Choose only for space-constrained non-automotive applications with sub-400 W surge exposure |
Compared with SMB8J40CAHE3/H and SMAJ40CA, the SMB8J40CAHM3/H provides the highest surge robustness (800 W), lowest thermal resistance, and full automotive qualification - making it the preferred choice for safety-critical vehicle subsystems requiring long-term reliability under thermal and electrical stress.
Availability
SMB8J40CAHM3/H is available at Aetrix Electronics and suitable for automotive sensor protection, CAN bus hardening, and industrial PLC I/O conditioning requiring stable component supply across extended production lifecycles.
Supply support for SMB8J40CAHM3/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, automotive qualification, and high-power density packaging.
The SMB8JxxCA series belongs to Vishay's TRANSZORB® TVS family, engineered specifically for high-energy transient suppression in harsh environments - especially automotive powertrain, chassis, and body electronics where AEC-Q101 compliance and thermal resilience are mandatory.
FAQ
What is the clamping voltage of SMB8J40CAHM3/H at its rated peak pulse current?
The SMB8J40CAHM3/H has a maximum clamping voltage (VC) of 64.5 V at its specified peak pulse current (IPPM) of 12.4 A under a 10/1000 μs waveform. This value is measured per ANSI/IEEE C62.35 and ensures downstream components see limited overvoltage during surge events. The SMB8J40CAHM3/H maintains this clamping performance across its full operating temperature range (-55 °C to +150 °C).
Is SMB8J40CAHM3/H suitable for automotive applications?
Yes, SMB8J40CAHM3/H is AEC-Q101 qualified and carries the HM3 suffix indicating halogen-free, RoHS-compliant construction with JESD201 Class 2 whisker resistance. It is explicitly intended for automotive use including engine control units, sensor modules, and infotainment systems. The SMB8J40CAHM3/H meets MSL Level 1 and is rated for TJ = +150 °C - fulfilling under-hood thermal and reliability requirements.
How does SMB8J40CAHM3/H differ from unidirectional variants like SMB10J40A?
The SMB8J40CAHM3/H is bidirectional with symmetrical breakdown (±44.4–49.1 V) and 800 W PPPM, whereas SMB10J40A is unidirectional (VBR = 44.4–49.1 V only in reverse), offers 1000 W PPPM, and includes forward surge rating (IFSM = 100 A). The SMB8J40CAHM3/H is optimized for AC/differential line protection (e.g., CAN, audio), while SMB10J40A suits DC power rail clamping where forward conduction matters.
What is the thermal resistance of SMB8J40CAHM3/H, and how does it affect layout design?
SMB8J40CAHM3/H has a typical junction-to-ambient thermal resistance (RθJA) of 72 °C/W when mounted on 0.2" × 0.2" copper pads per terminal, and RθJL = 20 °C/W. This means that at 800 W surge, junction temperature rise is ~16 °C above ambient - confirming safe operation without heatsinking. Layout must follow Vishay's recommended pad dimensions (0.086" min. width, 0.220" ref. length) to achieve these values; smaller pads increase thermal impedance and risk exceeding TJ max.
Does SMB8J40CAHM3/H have polarity markings, and how is it installed on PCB?
No, SMB8J40CAHM3/H has no polarity marking (e.g., cathode band) because it is a bidirectional TVS - both terminals are functionally identical. Installation requires no orientation check; the device can be placed in either direction across the protected line pair. This simplifies automated assembly and eliminates risk of reverse installation errors in differential or AC-coupled circuits protected by SMB8J40CAHM3/H.
SMB8J40CAHM3/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:
- Discontinued at Digi-Key
- 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/H FAQ
1.How can I place an order for SMB8J40CAHM3/H through Aetrix?
Please submit a Request for Quotation (RFQ) for SMB8J40CAHM3/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/H reliable?
The price and inventory of SMB8J40CAHM3/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/H is usually 5 days.
3.What payment methods are accepted for SMB8J40CAHM3/H?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMB8J40CAHM3/H transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMB8J40CAHM3/H?
SMB8J40CAHM3/H orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMB8J40CAHM3/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/H?
For technical support, including SMB8J40CAHM3/H datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMB8J40CAHM3/H requirements.
6.How does Aetrix verify that SMB8J40CAHM3/H is sourced from the original manufacturer or authorized distributors?
All SMB8J40CAHM3/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/H meets industry standards.
7.What is the process for return or replacement of SMB8J40CAHM3/H?
All SMB8J40CAHM3/H units undergo pre-shipment inspection (PSI). If there is an issue with SMB8J40CAHM3/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/H part is unused and in its original packaging.
Return procedure for SMB8J40CAHM3/H:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMB8J40CAHM3/H Tags
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