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Vishay General Semiconductor - Diodes Division SMBJ12A-M3/5B
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- Part No.:
- SMBJ12A-M3/5B
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SMBJ12A-M3/5B.pdf
- Description:
- TVS DIODE 12VWM 19.9VC DO214AA
- Quantity:
- Payment:
- Shipping:
Inventory:11,677
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Product details
Overview
SMBJ12A-M3/5B from Vishay General Semiconductor is a unidirectional surface-mount Transient Voltage Suppressor (TVS) diode in SMB (DO-214AA) package, designed for clamping voltage transients on power and signal lines. It features a 12 V stand-off voltage (VWM), 13.3–14.7 V breakdown voltage (VBR) at 1.0 mA test current, 19.9 V maximum clamping voltage (VC) at 30.2 A peak pulse current, and 600 W peak pulse power rating with 10/1000 µs waveform - deployed to protect MOSFETs, ICs, and sensor signal lines in industrial power supplies and telecom interfaces.
For engineers reviewing the SMBJ12A-M3/5B datasheet, SMBJ12A-M3/5B pinout, SMBJ12A-M3/5B application, or SMBJ12A-M3/5B equivalent, key selection criteria include unidirectional polarity, 19.9 V clamping performance under 30.2 A surge, thermal resistance of 100 °C/W (junction-to-ambient), and halogen-free RoHS-compliant construction per M3 suffix - critical for automotive-grade ESD robustness and board-level surge immunity validation.
Technical Context
This TVS diode operates as a voltage-clamping protection device in series with sensitive downstream circuitry, activating when reverse voltage exceeds its 13.3 V minimum breakdown threshold. Its glass-passivated junction enables sub-nanosecond response time and low incremental surge resistance, ensuring fast energy diversion during lightning-induced or inductive-switching transients.
The SMBJ12A-M3/5B is rated for 150 °C maximum junction temperature and derates linearly above 25 °C ambient per Fig. 2 in the datasheet. With 5.0 W steady-state power dissipation on infinite heatsink at 50 °C and 100 A non-repetitive forward surge capability (8.3 ms half-sine), it supports high-energy transient suppression without latch-up or thermal runaway.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM (Stand-off) | 12 V - Maximum continuous reverse operating voltage before conduction begins; defines safe operating margin below clamping threshold. |
| VBR (Breakdown) | 13.3–14.7 V at 1.0 mA - Confirmed breakdown range ensures reliable turn-on during overvoltage events without premature leakage. |
| VC (Clamping) | 19.9 V at 30.2 A (10/1000 µs) - Actual voltage seen by protected circuit during worst-case surge; limits stress on downstream ICs. |
| PPPM | 600 W - Peak transient power handling capacity; validates suitability for IEC 61000-4-5 Level 3/4 surge testing. |
| RθJA | 100 °C/W - Junction-to-ambient thermal resistance under standard PCB pad layout; informs thermal design margin for sustained operation. |
| TJ max. | +150 °C - Maximum allowable junction temperature; supports operation in under-hood automotive and industrial enclosures. |
| Package | SMB (DO-214AA) - Surface-mount outline with 0.205" × 0.130" footprint and matte tin-plated leads compliant with J-STD-002 solderability. |
Pinout & Package
Package: SMB (DO-214AA), surface-mount, unidirectional configuration with cathode band marking on one end. Dimensions: 0.205" × 0.130" × 0.084" (5.21 mm × 3.30 mm × 2.13 mm); meets UL 94 V-0 flammability rating.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward current entry / Surge return path | Connected to ground or low-impedance reference plane; completes clamping loop during transient events. |
| Cathode | Reverse-biased input / Protected line connection | Connected to the line being protected (e.g., 12 V rail or sensor output); conducts only when VIN > VBR. |
Key Features
| Feature | Design Value |
|---|---|
| 600 W peak pulse power (10/1000 µs) | Validates compliance with IEC 61000-4-5 surge immunity requirements for industrial and telecom equipment. |
| 19.9 V clamping voltage at 30.2 A | Ensures protected ICs experience ≤20 V stress during 30 A transients - critical for 12 V system rail integrity. |
| Halogen-free, RoHS-compliant (M3 suffix) | Meets environmental compliance mandates for automotive and EU-based industrial OEMs without compromising surge performance. |
| MSL Level 1 (J-STD-020), 260 °C peak reflow | Enables direct placement into standard lead-free SMT assembly lines without moisture sensitivity concerns. |
| 150 °C maximum junction temperature | Supports operation in high-temperature environments such as engine control units and outdoor base stations. |
Applications
| Industrial Power Supply Protection | Automotive Sensor Interface Protection |
|---|---|
|
Use Scenario: Suppresses load-dump and alternator ripple transients on 12 V DC input rails feeding PLC controllers and motor drives. IC Role / Device Role / Timing Role: Unidirectional TVS placed between input rail and ground, clamping surges before they reach DC/DC converters and microcontrollers. Use Value: Limits rail voltage to ≤19.9 V during 30.2 A transients, preventing overvoltage shutdown or latch-up in downstream 12 V-rated ICs. |
Use Scenario: Shields analog outputs of pressure/temperature sensors in ADAS modules from ESD and cable discharge events. IC Role / Device Role / Timing Role: TVS mounted directly at connector interface, shunting fast transients (<1 ns rise time) before signal conditioning amplifiers. Use Value: Sub-nanosecond response and 19.9 V clamping preserve signal fidelity and prevent ADC saturation or op-amp damage in 3.3 V/5 V sensor chains. |
| Telecom Line Interface Protection | Consumer Device USB Power Rail Protection |
|
Use Scenario: Protects Ethernet PHY power pins and bias rails in PoE-powered switches against induced lightning surges. IC Role / Device Role / Timing Role: Unidirectional clamp on 12 V or 24 V auxiliary supply lines, coordinated with common-mode chokes and gas discharge tubes. Use Value: 600 W pulse rating and 100 °C/W thermal resistance enable repeated surge handling without degradation in field-deployed infrastructure gear. |
Use Scenario: Guards 5 V USB VBUS lines in smart home hubs and set-top boxes against hot-plug and ESD events per IEC 61000-4-2 Level 4. IC Role / Device Role / Timing Role: Low-capacitance TVS placed adjacent to USB connector, grounded to chassis to divert ESD current away from USB controller. Use Value: 12 V stand-off allows normal 5 V operation while clamping to 19.9 V - sufficient headroom to avoid false triggering yet low enough to protect 5.5 V tolerant USB PHYs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ12A-E3/5B | Same electrical specs, but RoHS-compliant with lead-free finish (E3) instead of halogen-free (M3); no AEC-Q101 qualification. | Preferred for commercial-grade consumer electronics where halogen-free requirement is not mandated. | Select SMBJ12A-E3/5B when cost-sensitive commercial designs require RoHS compliance without halogen-free certification. |
| SMAJ12A-M3 | Lower 400 W peak pulse power, higher 23.2 V clamping voltage at 22.5 A, same 12 V VWM; SMA package (smaller footprint, higher RθJA). | Suitable for space-constrained layouts with lower surge threat levels (e.g., Class B IEC 61000-4-5). | Choose SMAJ12A-M3 only if board area is critical and surge energy is limited to ≤400 W - not drop-in for SMBJ12A-M3/5B's 600 W rating. |
Compared with SMBJ12A-E3/5B, the SMBJ12A-M3/5B adds halogen-free compliance for stricter environmental programs; versus SMAJ12A-M3, it delivers 50 % higher surge power handling and tighter clamping - making it essential for automotive and industrial applications demanding full IEC 61000-4-5 Level 4 resilience.
Availability
SMBJ12A-M3/5B is available at Aetrix Electronics and suitable for industrial power supplies, automotive sensor interfaces, telecom line protection, and consumer USB power rail protection requiring stable component supply across long production lifecycles.
Supply support for SMBJ12A-M3/5B 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, surge robustness, and automotive qualification.
The SMBJ series was engineered for high-energy transient suppression in harsh environments - targeting automotive, industrial, and telecom systems where failure due to voltage spikes must be eliminated.
FAQ
What is the clamping voltage of SMBJ12A-M3/5B at its rated peak pulse current?
The SMBJ12A-M3/5B has a maximum clamping voltage (VC) of 19.9 V when subjected to its rated peak pulse current of 30.2 A using the standardized 10/1000 µs waveform. This value is measured under defined test conditions per ANSI/IEEE C62.35 and represents the upper voltage limit imposed on protected circuitry during surge events - a critical parameter for ensuring downstream ICs remain within absolute maximum ratings. The SMBJ12A-M3/5B maintains this clamping performance consistently across its qualified operating temperature range.
Is SMBJ12A-M3/5B suitable for automotive applications?
Yes, SMBJ12A-M3/5B is halogen-free and RoHS-compliant per its M3 suffix, and AEC-Q101 qualified versions exist under ordering codes like SMBJ12AHM3_B/I. While the exact SMBJ12A-M3/5B variant shown here is commercial-grade, its electrical specs - including 150 °C TJ max, 100 A IFSM, and 600 W PPPM - align with automotive subsystem requirements such as body control modules and sensor interfaces. For certified automotive use, specify the HM3_X suffix variant; the SMBJ12A-M3/5B serves as the baseline commercial counterpart with identical surge performance.
How does the SMBJ12A-M3/5B differ from bidirectional TVS diodes like SMBJ12CA?
The SMBJ12A-M3/5B is unidirectional and functions only during reverse-voltage transients on a positively referenced line, with polarity marked by a cathode band. In contrast, SMBJ12CA is bidirectional and suppresses surges of either polarity - useful for AC lines or differential data buses. The SMBJ12A-M3/5B offers lower leakage at DC bias and is preferred for DC power rail protection, whereas SMBJ12CA sacrifices some VWM margin for symmetrical clamping. Both share identical package, power rating, and thermal specs, but the SMBJ12A-M3/5B must be oriented correctly on PCB to avoid forward conduction during normal operation.
What is the thermal resistance and how does it affect SMBJ12A-M3/5B layout?
The SMBJ12A-M3/5B has a typical junction-to-ambient thermal resistance (RθJA) of 100 °C/W when mounted on the recommended 0.2" × 0.2" copper pads per terminal. This value assumes standard JEDEC test conditions and directly impacts PCB layout: reducing pad size or omitting thermal vias increases actual RθJA, risking junction overheating during repetitive surges. To maintain reliability, designers must replicate the specified pad layout or add thermal relief and multiple vias - especially important since SMBJ12A-M3/5B can dissipate up to 5.0 W continuously at 50 °C ambient.
Can SMBJ12A-M3/5B replace older P6KE12A in existing designs?
No, SMBJ12A-M3/5B is not a direct replacement for P6KE12A due to fundamental package and surge profile differences: P6KE12A is through-hole (DO-15) with 600 W rating but slower response and higher clamping (20.1 V), while SMBJ12A-M3/5B is surface-mount (SMB/DO-214AA) with tighter 19.9 V clamping and optimized for automated assembly. PCB redesign is required to accommodate the smaller SMB footprint and revised pad layout. Although both meet 600 W 10/1000 µs, the SMBJ12A-M3/5B's lower RθJA and superior surge repetition capability make it preferable for new designs - but not a drop-in substitute for P6KE12A.
SMBJ12A-M3/5B 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:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 12V
- Voltage - Breakdown (Min):
- 13.3V
- Voltage - Clamping (Max) @ Ipp:
- 19.9V
- Current - Peak Pulse (10/1000µs):
- 30.2A
- Power - Peak Pulse:
- 600W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AA (SMBJ)
SMBJ12A-M3/5B FAQ
1.How can I place an order for SMBJ12A-M3/5B through Aetrix?
Please submit a Request for Quotation (RFQ) for SMBJ12A-M3/5B 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 SMBJ12A-M3/5B reliable?
The price and inventory of SMBJ12A-M3/5B are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMBJ12A-M3/5B is usually 5 days.
3.What payment methods are accepted for SMBJ12A-M3/5B?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMBJ12A-M3/5B transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMBJ12A-M3/5B?
SMBJ12A-M3/5B orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMBJ12A-M3/5B 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 SMBJ12A-M3/5B?
For technical support, including SMBJ12A-M3/5B datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMBJ12A-M3/5B requirements.
6.How does Aetrix verify that SMBJ12A-M3/5B is sourced from the original manufacturer or authorized distributors?
All SMBJ12A-M3/5B 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 SMBJ12A-M3/5B meets industry standards.
7.What is the process for return or replacement of SMBJ12A-M3/5B?
All SMBJ12A-M3/5B units undergo pre-shipment inspection (PSI). If there is an issue with SMBJ12A-M3/5B, 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 SMBJ12A-M3/5B part is unused and in its original packaging.
Return procedure for SMBJ12A-M3/5B:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMBJ12A-M3/5B Tags
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