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Vishay General Semiconductor - Diodes Division SMB8J28CAHM3/H
- Part No.:
- SMB8J28CAHM3/H
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SMB8J28CAHM3/H.pdf
- Description:
- TVS DIODE 28VWM 45.4VC DO214AA
- Quantity:
- Payment:
- Shipping:
Inventory:9,305
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Product details
Overview
SMB8J28CAHM3/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 28 V stand-off voltage (VWM), 31.1–34.4 V breakdown voltage (VBR) at 1 mA, 45.4 V maximum 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/H datasheet, SMB8J28CAHM3/H pinout, SMB8J28CAHM3/H application, or SMB8J28CAHM3/H equivalent, key selection criteria include AEC-Q101 qualification, bidirectional polarity, low clamping ratio (VC/VWM ≈ 1.62), MSL Level 1 moisture sensitivity, and halogen-free RoHS compliance per HM3 suffix.
Technical Context
This TVS diode operates as a voltage-clamped shunt protector, responding within <1 ps to transients induced by inductive switching or ESD events. Its glass-passivated junction ensures stable VBR tolerance and low leakage (<1 µA at VWM), while the SMB package enables automated placement and meets UL 94 V-0 flammability rating.
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. It complies with ANSI/IEEE C62.35 surge standards and delivers repeatable clamping performance under repetitive 10/1000 µs pulses when mounted on 5.0 mm × 5.0 mm copper pads.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 28 V - maximum continuous reverse operating voltage before clamping initiates |
| VBR min/max | 31.1 V / 34.4 V at 1 mA - defines tight breakdown window for predictable turn-on threshold |
| VC @ IPPM | 45.4 V at 17.6 A - limits downstream voltage stress during 800 W transient events |
| PPPM | 800 W (10/1000 µs) - energy-handling capacity for automotive load-dump and ISO 7637-2 pulse 5a |
| Leakage ID | ≤1.0 µA at 28 V - ensures minimal standby power loss in always-on circuits |
| TJ max | +150 °C - supports under-hood automotive environments without derating below 125 °C ambient |
| MSL Level | Level 1 (260 °C peak reflow) - compatible with standard SMT assembly without dry-pack requirements |
Pinout & Package
Package: SMB (DO-214AA), surface-mount, bidirectional - no polarity marking; symmetrical terminals.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode/Cathode (symmetrical) | Transient current path | Both terminals conduct identically during overvoltage events; no DC bias dependency |
| Case (body) | Thermal conduction path | Direct thermal interface to PCB copper; requires 5.0 mm × 5.0 mm pad per terminal for rated PPPM |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive-grade reliability including temperature cycling, HTRB, and ESD testing |
| Halogen-free & RoHS-compliant (HM3) | Meets JESD201 Class 2 whisker resistance and global environmental compliance mandates |
| Low clamping ratio (VC/VWM = 1.62) | Minimizes voltage overshoot across protected ICs compared to alternatives with >1.8 ratios |
| Glass-passivated junction | Ensures long-term VBR stability and reduced parameter drift over 15-year automotive service life |
| MSL Level 1 | Eliminates baking or humidity preconditioning prior to reflow, reducing manufacturing overhead |
Applications
| Automotive Sensor Interface | Industrial Digital I/O Protection |
|---|---|
Use Scenario: Protecting CAN/LIN bus transceivers and analog sensor inputs (e.g., pressure, temperature) from load-dump and jump-start transients in vehicle ECUs. IC Role / Device Role / Timing Role: Shunt-type transient suppressor placed directly at connector entry point, clamping surges before reaching signal conditioning circuitry. Use Value: Enables robust operation under ISO 7637-2 Pulse 5a (75 V/350 ms) with VC ≤ 45.4 V, preserving signal integrity of 3.3 V/5 V microcontrollers. | Use Scenario: Safeguarding PLC digital input modules against field-wiring induced surges from relay coils or motor drives. IC Role / Device Role / Timing Role: Bidirectional clamping element across 24 V DC input lines, absorbing ±1 kV EFT bursts per IEC 61000-4-4. Use Value: Maintains functional safety by limiting voltage excursion to <45.4 V during 800 W transients, preventing latch-up in optocoupler input stages. |
| Telecom Line Interface | Consumer Power Adapter ESD Protection |
Use Scenario: Shielding Ethernet PHY front-end and PoE detection circuitry from lightning-induced surges on RJ45 ports. IC Role / Device Role / Timing Role: Primary-level TVS on differential pairs, coordinated with secondary GDT or polymer PTC for staged protection. Use Value: Withstands 10/1000 µs surges up to 800 W while adding <0.5 pF capacitance - negligible impact on 100BASE-TX signal integrity. | Use Scenario: Guarding USB-C and barrel-jack inputs of smart home adapters against user-handling ESD (±8 kV contact). IC Role / Device Role / Timing Role: Fast-response shunt clamp on DC input rail, placed upstream of primary-side controller IC. Use Value: Sub-1 ps response time prevents voltage spikes from propagating to switching MOSFETs, reducing failure rate in high-volume consumer production. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMB8J28CAHE3/H | RoHS-compliant but not halogen-free; same electrical specs and AEC-Q101 qualification | Acceptable for commercial-automotive hybrids where halogen-free is not mandated | Select HE3 if halogen content is unrestricted and cost optimization is prioritized |
| SMAJ28CA | Lower PPPM (400 W), larger SMA package (DO-214AC), higher RθJA (90 °C/W) | Limited to lower-energy transients; unsuitable for ISO 7637-2 Pulse 5a | Choose only for space-constrained non-automotive designs with <400 W surge requirements |
Compared with SMB8J28CAHM3/H, the HE3 variant offers identical surge performance without halogen-free assurance, while SMAJ28CA trades 50 % power rating and thermal performance for legacy footprint compatibility - making HM3 the optimal choice for AEC-Q101-compliant, high-reliability 800 W protection.
Availability
SMB8J28CAHM3/H is available at Aetrix Electronics and suitable for automotive ECU design, industrial PLC I/O modules, and telecom line card development requiring stable component supply and full AEC-Q101 traceability.
Supply support for SMB8J28CAHM3/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 and automotive qualification.
The SMB8JxxCA series belongs to Vishay's TRANSZORB® TVS platform, engineered specifically for high-power-density, AEC-Q101-compliant transient suppression in harsh automotive and industrial environments.
FAQ
What is the clamping voltage of SMB8J28CAHM3/H at its rated peak pulse current?
The SMB8J28CAHM3/H has a maximum clamping voltage (VC) of 45.4 V at its rated peak pulse current (IPPM) of 17.6 A, measured under the standardized 10/1000 µs waveform. This value ensures protected downstream components experience no more than 45.4 V during an 800 W transient event. The clamping performance is guaranteed across the full operating temperature range (-55 °C to +150 °C) when mounted per the recommended 5.0 mm × 5.0 mm copper pad layout.
Is SMB8J28CAHM3/H qualified for automotive applications?
Yes, SMB8J28CAHM3/H is AEC-Q101 qualified and carries the HM3 suffix indicating halogen-free, RoHS-compliant construction validated for automotive use. It undergoes rigorous stress testing including temperature cycling, high-temperature reverse bias (HTRB), and ESD per JESD22-A114. The device is explicitly listed in Vishay's AEC-Q101 qualified products table and intended for under-hood and chassis-mounted ECUs where reliability under thermal and mechanical stress is critical. SMB8J28CAHM3/H meets all requirements for ISO 7637-2 and ISO 16750-2 compliance when applied per datasheet guidelines.
How does the SMB8J28CAHM3/H differ from unidirectional variants like SMB10J28A?
SMB8J28CAHM3/H is bidirectional with symmetrical clamping behavior for AC or floating-line protection, whereas SMB10J28A is unidirectional and conducts only in reverse bias. SMB8J28CAHM3/H has lower peak pulse power (800 W vs. 1000 W) and lower IPPM (17.6 A vs. 22.0 A) due to bidirectional architecture trade-offs. Its VWM is identical (28 V), but it lacks forward surge rating (IFSM) since it does not conduct DC forward current. SMB8J28CAHM3/H is preferred for data lines and differential signals; SMB10J28A suits DC power rail protection where polarity is fixed.
What is the thermal resistance profile of SMB8J28CAHM3/H, and how does it affect layout?
SMB8J28CAHM3/H has a typical junction-to-ambient thermal resistance (RθJA) of 72 °C/W and junction-to-lead (RθJL) of 20 °C/W when mounted on the specified 0.2" × 0.2" (5.0 mm × 5.0 mm) copper pads per terminal. This means PCB layout must allocate ≥25 mm² of 2-oz copper per pad to sustain full 800 W pulse rating without exceeding TJ max of +150 °C. Reducing pad area increases RθJA proportionally, derating IPPM and PPPM - e.g., halving pad size raises RθJA to ~110 °C/W, limiting usable surge energy by ~35 %. Thermal vias under pads further improve heat dissipation in multilayer boards.
Does SMB8J28CAHM3/H require special handling during PCB assembly?
No, SMB8J28CAHM3/H is rated MSL Level 1 per J-STD-020, meaning it can be stored indefinitely at ambient conditions and processed through standard lead-free reflow profiles (peak 260 °C) without baking or dry-packing. Its matte tin-plated leads comply with J-STD-002 and JESD22-B102 for solderability, and it passes JESD201 Class 2 whisker testing. The HM3 suffix confirms halogen-free molding compound and termination, eliminating concerns about corrosive residue or post-reflow halogen outgassing in sealed enclosures. No special stencil or placement adjustments are needed beyond standard SMB (DO-214AA) fiducial alignment.
SMB8J28CAHM3/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):
- 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/H FAQ
1.How can I place an order for SMB8J28CAHM3/H through Aetrix?
Please submit a Request for Quotation (RFQ) for SMB8J28CAHM3/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 SMB8J28CAHM3/H reliable?
The price and inventory of SMB8J28CAHM3/H are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMB8J28CAHM3/H is usually 5 days.
3.What payment methods are accepted for SMB8J28CAHM3/H?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMB8J28CAHM3/H transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMB8J28CAHM3/H?
SMB8J28CAHM3/H orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMB8J28CAHM3/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 SMB8J28CAHM3/H?
For technical support, including SMB8J28CAHM3/H datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMB8J28CAHM3/H requirements.
6.How does Aetrix verify that SMB8J28CAHM3/H is sourced from the original manufacturer or authorized distributors?
All SMB8J28CAHM3/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 SMB8J28CAHM3/H meets industry standards.
7.What is the process for return or replacement of SMB8J28CAHM3/H?
All SMB8J28CAHM3/H units undergo pre-shipment inspection (PSI). If there is an issue with SMB8J28CAHM3/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 SMB8J28CAHM3/H part is unused and in its original packaging.
Return procedure for SMB8J28CAHM3/H:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMB8J28CAHM3/H Tags
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