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Vishay General Semiconductor - Diodes Division SMB8J28CAHM3_B/I
- Part No.:
- SMB8J28CAHM3_B/I
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SMB8J28CAHM3_B/I.pdf
- Description:
- 800W,28V 5%,BIDIR,SMB TVS
- Quantity:
- Payment:
- Shipping:
Inventory:7,006
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Product details
Overview
SMB8J28CAHM3_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 28 V stand-off voltage (VWM), 31.1–34.4 V breakdown voltage (VBR) at 1 mA, 45.4 V clamping voltage (VC) at 17.6 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 SMB8J28CAHM3_B/I datasheet, SMB8J28CAHM3_B/I pinout, SMB8J28CAHM3_B/I application, or SMB8J28CAHM3_B/I equivalent, this device is selected for AEC-Q101-qualified bidirectional overvoltage suppression where low clamping ratio, MSL Level 1 reliability, and halogen-free RoHS compliance are required in space-constrained surface-mount designs.
Technical Context
This bidirectional TVS operates symmetrically across both polarities, enabling protection of AC-coupled or differential signal paths without polarity sensitivity. Its glass-passivated junction ensures stable VBR tolerance and low leakage (<1.0 µA at VWM), while the low incremental surge resistance supports fast clamping response under repetitive transients.
The device is rated for -55 °C to +150 °C operating junction temperature, with thermal resistance RθJA = 72 °C/W and RθJL = 20 °C/W, confirming suitability for thermally demanding automotive under-hood and industrial control environments when mounted per recommended 0.2" × 0.2" copper pads.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 28 V - Maximum continuous reverse working voltage before conduction begins; defines safe operating margin for 24 V nominal systems. |
| VBR min/max | 31.1 V / 34.4 V at IT = 1 mA - Tight breakdown window ensures predictable turn-on during ESD or load-dump events. |
| VC @ IPPM | 45.4 V at 17.6 A - Clamping voltage limits downstream IC stress during 800 W transient surges (10/1000 µs). |
| PPPM | 800 W - Peak pulse power rating determines survivability against ISO 7637-2 Pulse 1/2/5a and IEC 61000-4-5 surges. |
| ID @ VWM | <1.0 µA - Ultra-low leakage preserves signal integrity and battery life in always-on sensor circuits. |
| TJ max | +150 °C - Enables use in engine control units, motor drives, and other high-temperature automotive modules. |
| AEC-Q101 | Qualified - Validated for automotive-grade reliability including temperature cycling, HTRB, and ESD testing per JESD47. |
Pinout & Package
Package: SMB (DO-214AA), surface-mount, halogen-free, RoHS-compliant, MSL Level 1 (260 °C peak reflow). Cathode band absent - bidirectional symmetry eliminates polarity marking.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode/Cathode (symmetrical) | Transient current path | Both terminals conduct identically during positive or negative surges; no directional mounting required. |
| Case (body) | Thermal and mechanical interface | Exposed metal slug provides primary heat dissipation path to PCB copper; requires minimum 0.2" × 0.2" pad per terminal. |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional clamping | Enables single-device protection of AC signals, RS-485 buses, or dual-rail sensors without external polarity management. |
| AEC-Q101 qualification | Validates robustness for automotive applications including engine control, ADAS camera links, and body electronics. |
| Halogen-free & RoHS-compliant (HM3 suffix) | Meets automotive OEM environmental requirements and supports lead-free assembly with J-STD-002 solderability. |
| Low clamping ratio (VC/VBR ≈ 1.36) | Minimizes voltage overshoot during transients, reducing risk of latch-up or gate oxide damage in protected MOSFETs or MCUs. |
| MSL Level 1 rating | Allows unlimited floor life and standard reflow profiles up to 260 °C peak, simplifying SMT manufacturing. |
Applications
| Automotive Sensor Protection | Industrial I/O Interface |
|---|---|
|
Use Scenario: Protecting LIN bus transceivers and analog sensor outputs (e.g., pressure, temperature) from load dump and jump-start transients in vehicle ECUs. IC Role / Device Role / Timing Role: Bidirectional TVS clamps ±100 V surges within nanoseconds to prevent damage to 5 V or 3.3 V signal conditioning circuitry. Use Value: Eliminates need for separate unidirectional devices on differential pairs, reducing BOM count and PCB area in compact modules. |
Use Scenario: Shielding PLC analog input channels (4–20 mA, 0–10 V) from field-induced surges caused by relay switching or lightning coupling. IC Role / Device Role / Timing Role: Fast-response voltage clamp limits transient energy delivered to precision op-amps and ADC front-ends. Use Value: Maintains measurement accuracy by holding clamped voltage below 45.4 V, preventing saturation or destruction of downstream signal chain components. |
| Telecom Line Interface | Consumer USB Port Protection |
|
Use Scenario: Safeguarding Ethernet PHY magnetics and PoE injectors against induced surges on outdoor telecom line cards. IC Role / Device Role / Timing Role: Bidirectional suppression absorbs common-mode transients across twisted-pair data lines without disrupting DC bias. Use Value: Supports IEEE 802.3af/at compliance by surviving repeated 800 W surges while maintaining low capacitance (<100 pF at 0 V). |
Use Scenario: Adding secondary-level surge immunity to USB 2.0 data lines (D+/D−) in smart home hubs exposed to ESD and cable discharge events. IC Role / Device Role / Timing Role: Low-leakage (≤1 µA) TVS prevents signal attenuation while clamping ESD pulses to <45.4 V in <1 ns. Use Value: Preserves USB eye diagram integrity and meets IEC 61000-4-2 Level 4 (±15 kV air/±8 kV contact) without degrading data rate. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar bidirectional TVS protection applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMB8J28CAHE3_B/I | Same electrical specs, but RoHS-compliant commercial grade (non-halogen-free); lacks AEC-Q101 qualification. | Suitable for non-automotive industrial or consumer applications where halogen-free requirement is not mandated. | Select when cost optimization is prioritized and automotive qualification is unnecessary. |
| SMAJ28CA | Lower PPPM (400 W), larger SMA package (DO-214AC), higher RθJA (90 °C/W); same VWM/VBR/VC ratings. | Acceptable for lower-energy surge environments (e.g., IEC 61000-4-5 2 kV) where board space allows larger footprint. | Choose only if SMB footprint is unavailable and thermal derating can be accommodated via larger copper areas. |
Compared with SMB8J28CAHM3_B/I, the HE3 variant trades halogen-free compliance and AEC-Q101 validation for lower cost, while the SMAJ28CA sacrifices power handling and thermal performance for legacy package compatibility - making SMB8J28CAHM3_B/I optimal for next-gen automotive and high-reliability industrial designs.
Availability
SMB8J28CAHM3_B/I is available at Aetrix Electronics and suitable for automotive sensor modules, industrial PLC I/O cards, telecom line interface boards, and consumer USB hub designs requiring stable component supply with full traceability and long-term lifecycle support.
Supply support for SMB8J28CAHM3_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 diodes, rectifiers, MOSFETs, and protection devices with emphasis on reliability, efficiency, and application-specific optimization.
The SMB8JxxCA series targets AEC-Q101-compliant transient suppression for automotive and industrial systems where bidirectional clamping, low leakage, and high power density are critical design constraints.
FAQ
What is the clamping voltage of SMB8J28CAHM3_B/I at its rated peak pulse current?
The SMB8J28CAHM3_B/I has a maximum clamping voltage (VC) of 45.4 V at 17.6 A peak pulse current (IPPM), measured with a 10/1000 µs waveform. This value defines the upper voltage limit imposed on protected circuitry during an 800 W transient event, ensuring downstream components like microcontrollers or transceivers remain within safe operating voltage margins. The SMB8J28CAHM3_B/I achieves this with a clamping ratio of approximately 1.36 relative to its VBR midpoint.
Is SMB8J28CAHM3_B/I suitable for automotive applications?
Yes, SMB8J28CAHM3_B/I is AEC-Q101 qualified and carries the HM3 suffix indicating halogen-free, RoHS-compliant construction - meeting stringent automotive reliability requirements for under-hood and chassis-mounted electronics. It is explicitly rated for operation from -55 °C to +150 °C junction temperature and validated for temperature cycling, high-temperature reverse bias, and ESD robustness. The SMB8J28CAHM3_B/I is commonly used in ADAS camera modules, body control units, and powertrain sensor interfaces.
How does the bidirectional nature of SMB8J28CAHM3_B/I affect PCB layout?
The SMB8J28CAHM3_B/I has symmetrical bidirectional conduction, so polarity orientation on the PCB is irrelevant - no cathode band or marking is present. This eliminates orientation errors during automated placement and simplifies layout for differential or AC-coupled lines such as RS-485, CAN FD, or audio inputs. Designers must still adhere to the recommended 0.2" × 0.2" copper pad per terminal for thermal performance and surge current handling, but no silkscreen polarity indicator is needed for the SMB8J28CAHM3_B/I.
What is the leakage current specification for SMB8J28CAHM3_B/I at its stand-off voltage?
The SMB8J28CAHM3_B/I specifies a maximum reverse leakage current (ID) of 1.0 µA at its 28 V stand-off voltage (VWM), tested at 25 °C. This ultra-low leakage preserves signal integrity in high-impedance sensor interfaces and extends battery life in always-on automotive modules. The value remains stable across temperature due to the device's glass-passivated junction, and it is verified per ANSI/IEEE C62.35 standards - a key differentiator from generic TVS diodes with higher leakage.
Does SMB8J28CAHM3_B/I require special handling during reflow soldering?
No special handling beyond standard SMT practices is required for SMB8J28CAHM3_B/I. It is rated MSL Level 1 per J-STD-020, meaning it has unlimited floor life and withstands peak reflow temperatures up to 260 °C without baking. The matte tin-plated leads comply with J-STD-002 and JESD22-B102 for solderability, and the package passes JESD201 Class 2 whisker testing. These attributes ensure robust manufacturability in high-volume automotive and industrial assembly lines using the SMB8J28CAHM3_B/I.
SMB8J28CAHM3_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):
- 28V
- Voltage - Breakdown (Min):
- 31.1V
- Voltage - Clamping (Max) @ Ipp:
- 28V
- Current - Peak Pulse (10/1000µs):
- 17.6A
- 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)
SMB8J28CAHM3_B/I FAQ
1.How can I place an order for SMB8J28CAHM3_B/I through Aetrix?
Please submit a Request for Quotation (RFQ) for SMB8J28CAHM3_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 SMB8J28CAHM3_B/I reliable?
The price and inventory of SMB8J28CAHM3_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 SMB8J28CAHM3_B/I is usually 5 days.
3.What payment methods are accepted for SMB8J28CAHM3_B/I?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMB8J28CAHM3_B/I transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMB8J28CAHM3_B/I?
SMB8J28CAHM3_B/I orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMB8J28CAHM3_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 SMB8J28CAHM3_B/I?
For technical support, including SMB8J28CAHM3_B/I datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMB8J28CAHM3_B/I requirements.
6.How does Aetrix verify that SMB8J28CAHM3_B/I is sourced from the original manufacturer or authorized distributors?
All SMB8J28CAHM3_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 SMB8J28CAHM3_B/I meets industry standards.
7.What is the process for return or replacement of SMB8J28CAHM3_B/I?
All SMB8J28CAHM3_B/I units undergo pre-shipment inspection (PSI). If there is an issue with SMB8J28CAHM3_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 SMB8J28CAHM3_B/I part is unused and in its original packaging.
Return procedure for SMB8J28CAHM3_B/I:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMB8J28CAHM3_B/I Tags
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