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Vishay General Semiconductor - Diodes Division SMB8J28CAHM3_A/I
- Part No.:
- SMB8J28CAHM3_A/I
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SMB8J28CAHM3_A/I.pdf
- Description:
- TVS DIODE 28VWM 45.4VC DO214AA
- Quantity:
- Payment:
- Shipping:
Inventory:3,514
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Product details
Overview
SMB8J28CAHM3_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 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_A/I datasheet, SMB8J28CAHM3_A/I pinout, SMB8J28CAHM3_A/I application, or SMB8J28CAHM3_A/I equivalent, key selection criteria include bidirectional clamping capability, AEC-Q101 qualification, low clamping ratio (VC/VWM ≈ 1.62), MSL Level 1 moisture sensitivity, and halogen-free RoHS compliance per HM3 suffix.
Technical Context
This device operates as a voltage-clamped crowbar during transients, leveraging an avalanche junction to clamp reverse surges up to 800 W without failure. Its bidirectional symmetry enables protection of AC-coupled or differential lines without polarity constraints, and its 1.0 µA max reverse leakage at VWM ensures minimal standby power impact on sensitive analog or digital inputs.
The SMB8J28CAHM3_A/I exhibits a thermal resistance of 72 °C/W (junction-to-ambient) and 20 °C/W (junction-to-lead), supporting reliable operation up to +150 °C junction temperature. Its glass-passivated chip construction and matte tin-plated leads meet J-STD-002 solderability and JESD22-B102 whisker resistance Class 2 requirements.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 28 V - maximum continuous reverse operating voltage before clamping begins; defines safe working range for protected circuitry. |
| VBR (min/max) | 31.1 V / 34.4 V at 1 mA - guaranteed avalanche initiation window; ensures consistent turn-on across production lots. |
| VC @ IPPM | 45.4 V at 17.6 A - clamped voltage under 10/1000 µs surge; limits stress on downstream ICs like microcontrollers or transceivers. |
| PPPM | 800 W - peak transient energy absorption capacity; supports IEC 61000-4-5 Level 3 (1 kV/2 Ω) surge immunity. |
| ID @ VWM | 1.0 µA - ultra-low reverse leakage at stand-off voltage; preserves signal integrity in high-impedance sensor front-ends. |
| TJ max | +150 °C - maximum junction temperature; enables deployment in under-hood automotive or industrial control environments. |
| Package | SMB (DO-214AA) - surface-mount outline with 5.59 mm × 3.94 mm footprint; compatible with automated pick-and-place and reflow. |
Pinout & Package
SMB8J28CAHM3_A/I uses the standard SMB (DO-214AA) package: two-terminal, non-polarized bidirectional device with no cathode marking. The case is molded epoxy meeting UL 94 V-0; terminals are matte tin-plated for J-STD-002-compliant solderability.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode/Cathode (symmetrical) | Bidirectional avalanche junction | No polarity marking required; either terminal serves as input/output for AC or differential line protection. |
| Case (exposed pad not present) | Thermal and mechanical anchor | Mounts directly to PCB copper pads (0.2" × 0.2") for thermal dissipation; no internal thermal pad or ground connection. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive applications including engine control modules and ADAS sensor interfaces per stress test requirements. |
| Halogen-free & RoHS-compliant (HM3) | Meets automotive environmental standards and end-of-life recycling mandates without compromising surge robustness. |
| Low clamping ratio (VC/VWM = 1.62) | Minimizes overvoltage exposure during transients-critical for 3.3 V or 5 V logic interfacing with unprotected analog sensors. |
| MSL Level 1 (260 °C peak) | Enables single-reflow assembly without baking or special handling; reduces manufacturing cost and risk of moisture-induced defects. |
| Glass-passivated junction | Ensures stable VBR and low leakage over temperature and lifetime-superior to epoxy-passivated alternatives in harsh environments. |
Applications
| Automotive Sensor Protection | Industrial Digital I/O Protection |
|---|---|
Use Scenario: Protecting LIN bus transceivers and pressure/temperature sensor outputs from load dump and ESD in vehicle cabins. IC Role / Device Role / Timing Role: Bidirectional TVS placed between sensor output and MCU input to clamp ±30 kV ESD (IEC 61000-4-2) and 100 V/50 ms load dump spikes. Use Value: Prevents latch-up or gate oxide damage in 3.3 V automotive MCUs while maintaining <1 µA leakage at 28 V system rail. |
Use Scenario: Safeguarding PLC digital input cards against inductive kickback from solenoid/relay coils in factory automation. IC Role / Device Role / Timing Role: Standoff clamping device on 24 V DC input lines, absorbing 800 W surges without degradation over >10,000 events. Use Value: Eliminates need for external series resistors or RC snubbers-reducing BOM count and board space while sustaining >150 °C ambient operation. |
| Telecom Line Interface | Consumer USB Port ESD Protection |
Use Scenario: Shielding RS-485 transceiver pairs in outdoor security cameras exposed to lightning-induced surges on long cable runs. IC Role / Device Role / Timing Role: Differential-mode TVS across A/B lines, providing symmetrical clamping to preserve common-mode rejection during 1 kV/2 Ω IEC 61000-4-5 surges. Use Value: Maintains signal integrity below 100 pF junction capacitance at zero bias-no data rate degradation up to 20 Mbps. |
Use Scenario: Adding secondary-level ESD protection on USB 2.0 D+/D− lines behind primary TVS in smart home hubs and docking stations. IC Role / Device Role / Timing Role: Low-leakage bidirectional clamp limiting voltage to ≤45.4 V during ±15 kV contact discharge, preventing PHY layer latch-up. Use Value: Complies with USB-IF ESD stress requirements while adding <0.1 mm² footprint overhead-no layout redesign needed. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMB8J28CAHE3_A/I | Same electrical specs and SMB package, but RoHS-compliant commercial-grade (non-halogen-free); lacks HM3 halogen-free certification. | Suitable for non-automotive industrial use where halogen-free mandate does not apply; lower cost than HM3 variant. | Select when AEC-Q101 is not required and halogen-free compliance is optional. |
| SMAJ28CAHM3_A/I | Same VWM/VBR/VC ratings but in smaller SMA (DO-214AC) package; 600 W PPPM (vs. 800 W); higher thermal resistance (RθJA = 95 °C/W). | Limited to lower-energy surges (e.g., IEC 61000-4-2 only); unsuitable for IEC 61000-4-5 Level 3 or automotive load dump. | Choose only if board space is constrained and peak surge energy remains ≤600 W. |
Compared with SMB8J28CAHE3_A/I, the SMB8J28CAHM3_A/I adds halogen-free compliance for automotive supply chains; versus SMAJ28CAHM3_A/I, it delivers 33 % higher surge power handling and 24 % better thermal performance-critical for under-hood reliability.
Availability
SMB8J28CAHM3_A/I is available at Aetrix Electronics and suitable for automotive sensor interfaces, industrial PLC I/O modules, telecom line drivers, and consumer USB port protection requiring stable component supply across multi-year production cycles.
Supply support for SMB8J28CAHM3_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, rectifiers, MOSFETs, and protection devices with emphasis on reliability, power density, and automotive qualification.
The SMB8J28CAHM3_A/I belongs to Vishay's TRANSZORB® family of high-power TVS diodes, engineered specifically for robust transient suppression in harsh environments-including AEC-Q101-compliant automotive subsystems and industrial control systems.
FAQ
What is the clamping voltage of SMB8J28CAHM3_A/I at its rated peak pulse current?
The SMB8J28CAHM3_A/I has a maximum clamping voltage (VC) of 45.4 V when subjected to its specified peak pulse current (IPPM) of 17.6 A using the 10/1000 µs waveform. This value is measured per ANSI/IEEE C62.35 and guarantees that downstream components experience no more than 45.4 V during standardized surge events - a critical parameter for protecting 3.3 V or 5 V logic interfaces. The SMB8J28CAHM3_A/I maintains this clamping performance across its full operating temperature range.
Is SMB8J28CAHM3_A/I suitable for automotive applications?
Yes, SMB8J28CAHM3_A/I is AEC-Q101 qualified and carries the HM3 suffix indicating halogen-free, RoHS-compliant construction - meeting automotive supply chain requirements for under-hood and cabin electronics. It is explicitly rated for operation from −55 °C to +150 °C junction temperature and validated for mechanical shock, temperature cycling, and humidity testing per AEC-Q101. The SMB8J28CAHM3_A/I is commonly used in automotive sensor modules, body control units, and infotainment interface protection.
How does the SMB8J28CAHM3_A/I differ from unidirectional variants like SMB10J28A?
The SMB8J28CAHM3_A/I is bidirectional with symmetrical clamping for AC or differential signal lines, whereas SMB10J28A is unidirectional and requires correct polarity orientation. SMB8J28CAHM3_A/I offers 800 W peak pulse power and 17.6 A IPPM, while SMB10J28A provides 1000 W and 22.0 A - reflecting higher surge capacity for DC-biased applications. Both share identical VWM (28 V) and VBR (31.1–34.4 V), but only SMB8J28CAHM3_A/I supports bidirectional transients without external circuitry.
What is the moisture sensitivity level (MSL) rating for SMB8J28CAHM3_A/I?
SMB8J28CAHM3_A/I is rated MSL Level 1 per J-STD-020, with a maximum lead finish reflow peak temperature of 260 °C. This means the device can be stored indefinitely at ambient conditions and assembled using standard lead-free reflow profiles without baking or dry-pack requirements - simplifying manufacturing logistics and reducing risk of popcorning or delamination. The SMB8J28CAHM3_A/I achieves this via robust molding compound and hermetic glass passivation.
Does SMB8J28CAHM3_A/I require a heatsink for 800 W surge dissipation?
No, SMB8J28CAHM3_A/I does not require an external heatsink for single-event 800 W surge dissipation because the 10/1000 µs pulse duration results in extremely short thermal time constants - energy is absorbed transiently by the junction, not conducted continuously. Its RθJA of 72 °C/W applies to steady-state conditions, but surge events last milliseconds. Proper PCB copper pad layout (0.2" × 0.2" per terminal) is sufficient for thermal management; no additional heatsinking is specified or recommended for compliant operation.
SMB8J28CAHM3_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):
- 28V
- Voltage - Breakdown (Min):
- 31.1V
- Voltage - Clamping (Max) @ Ipp:
- 45.4V
- 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_A/I FAQ
1.How can I place an order for SMB8J28CAHM3_A/I through Aetrix?
Please submit a Request for Quotation (RFQ) for SMB8J28CAHM3_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 SMB8J28CAHM3_A/I reliable?
The price and inventory of SMB8J28CAHM3_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 SMB8J28CAHM3_A/I is usually 5 days.
3.What payment methods are accepted for SMB8J28CAHM3_A/I?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMB8J28CAHM3_A/I transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMB8J28CAHM3_A/I?
SMB8J28CAHM3_A/I orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMB8J28CAHM3_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 SMB8J28CAHM3_A/I?
For technical support, including SMB8J28CAHM3_A/I datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMB8J28CAHM3_A/I requirements.
6.How does Aetrix verify that SMB8J28CAHM3_A/I is sourced from the original manufacturer or authorized distributors?
All SMB8J28CAHM3_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 SMB8J28CAHM3_A/I meets industry standards.
7.What is the process for return or replacement of SMB8J28CAHM3_A/I?
All SMB8J28CAHM3_A/I units undergo pre-shipment inspection (PSI). If there is an issue with SMB8J28CAHM3_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 SMB8J28CAHM3_A/I part is unused and in its original packaging.
Return procedure for SMB8J28CAHM3_A/I:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMB8J28CAHM3_A/I Tags
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