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Vishay General Semiconductor - Diodes Division SMBJ12A/54
- Part No.:
- SMBJ12A/54
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SMBJ12A/54.pdf
- Description:
- TVS DIODE 12VWM 19.9VC DO214AA
- Quantity:
- Payment:
- Shipping:
Inventory:7,854
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Product details
Overview
SMBJ12A/54 from Vishay General Semiconductor is a unidirectional surface-mount Transient Voltage Suppressor (TVS) diode in the SMB (DO-214AA) package, designed to protect sensitive electronics against voltage transients induced by inductive load switching and lightning surges. It features a 12 V stand-off voltage (VWM), 13.3–14.7 V breakdown voltage (VBR) at 1 mA, 19.9 V maximum clamping voltage (VC) at 30.2 A peak pulse current (IPPM), and 600 W peak pulse power (PPPM) with a 10/1000 µs waveform - deployed on IC power rails, MOSFET gate drivers, and sensor signal lines in industrial control systems.
For engineers reviewing the SMBJ12A/54 datasheet, SMBJ12A/54 pinout, SMBJ12A/54 application, or SMBJ12A/54 equivalent, this page delivers verified electrical parameters, thermal derating behavior, clamping performance under surge conditions, and real-world protection use cases for automotive-grade and industrial-grade PCB designs requiring robust ESD and surge immunity per IEC 61000-4-2/4-5.
Technical Context
The SMBJ12A/54 operates as a unidirectional avalanche diode, conducting only in reverse bias above its breakdown threshold to shunt transient energy to ground. Its glass-passivated junction ensures stable VBR tolerance (±5%) and low incremental surge resistance, enabling consistent clamping across repetitive 10/1000 µs pulses at 0.01% duty cycle.
Thermal design relies on its RθJA of 100 °C/W and RθJL of 20 °C/W, with derating required above TA = 25 °C per Figure 2; it supports operation from –55 °C to +150 °C junction temperature and meets MSL Level 1 per J-STD-020 with 260 °C reflow peak.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM (Stand-off Voltage) | 12 V - Maximum continuous reverse voltage before significant leakage; defines safe operating margin below clamping onset. |
| VBR (Breakdown Voltage) | 13.3–14.7 V at 1 mA - Guaranteed avalanche initiation range; ensures predictable turn-on during transients. |
| VC (Clamping Voltage) | 19.9 V at IPPM = 30.2 A - Peak voltage seen by protected circuit during 600 W surge; determines downstream component stress. |
| PPPM (Peak Pulse Power) | 600 W (10/1000 µs) - Transient energy-handling capacity; validates suitability for IEC 61000-4-5 Level 4 (4 kV) surge testing. |
| ID (Reverse Leakage) | 5.0 µA max at VWM - Minimal standby power loss and signal integrity impact in high-impedance circuits. |
| TJ max. | +150 °C - Enables deployment in under-hood automotive or enclosed industrial enclosures without forced cooling. |
| Package | SMB (DO-214AA) - Standardized surface-mount footprint compatible with automated placement and IPC-7351B land patterns. |
Pinout & Package
Package: SMB (DO-214AA), molded plastic case with matte tin-plated leads; polarity indicated by cathode band on the body end.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (unmarked end) | Forward conduction terminal | Connected to protected line (e.g., VCC or signal); conducts forward current only during fault conditions in unidirectional mode. |
| Cathode (banded end) | Avalanche clamping terminal | Connected to ground or low-impedance return path; initiates clamping when reverse voltage exceeds VBR. |
Key Features
| Feature | Design Value |
|---|---|
| 600 W peak pulse power (10/1000 µs) | Supports IEC 61000-4-5 surge immunity up to 4 kV in industrial and automotive subsystems without external heat sinking. |
| Low clamping ratio (VC/VBR ≈ 1.42) | Minimizes overvoltage stress on downstream ICs - critical for 12 V rail protection of microcontrollers and CAN transceivers. |
| Glass-passivated junction | Ensures long-term stability of VBR and low leakage drift over temperature and lifetime, even under repeated surge events. |
| MSL Level 1 (260 °C peak) | Enables standard lead-free reflow assembly without moisture sensitivity concerns or baking requirements. |
| AEC-Q101 qualified variants available | HE3/HM3 suffix versions meet automotive reliability standards for engine control, body electronics, and ADAS sensor interfaces. |
Applications
| Automotive Body Control Module (BCM) | Industrial PLC Digital Input Card |
|---|---|
|
Use Scenario: Protecting 12 V supply inputs of BCM microcontrollers from load-dump transients (ISO 7637-2 Pulse 5a) and alternator ripple. IC Role / Device Role / Timing Role: Unidirectional TVS placed between VBAT and GND, clamping surges within 1 ns to limit voltage to ≤20 V. Use Value: Prevents latch-up or permanent damage to 3.3 V/5 V logic supplies downstream of DC-DC converters during vehicle cranking or battery disconnection events. |
Use Scenario: Shielding 24 V digital input optocouplers from field-wiring induced surges in factory automation cabinets. IC Role / Device Role / Timing Role: Standoff-rated TVS on each input channel, absorbing 1 kV/500 A transients per IEC 61000-4-5. Use Value: Eliminates false triggering and extends optocoupler lifetime by limiting transient-induced forward-bias stress on internal LEDs. |
| Telecom Power Supply Front-End | Consumer Appliance Motor Driver Board |
|
Use Scenario: Safeguarding AC-DC converter primary-side controllers against lightning-induced surges entering via AC mains. IC Role / Device Role / Timing Role: Secondary-side TVS on 12 V bias rail, triggered by coupled transients from Y-capacitor paths. Use Value: Maintains controller uptime during 1.2/50 µs surge events by clamping to 19.9 V - well below 24 V UVLO thresholds. |
Use Scenario: Suppressing commutation spikes from brushed DC motors in washing machine control boards. IC Role / Device Role / Timing Role: TVS across motor terminals and H-bridge FET drains, diverting inductive kickback energy. Use Value: Reduces EMI radiation and prevents gate oxide rupture in 40 V logic-level MOSFETs during rapid PWM switching. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ12CA | Bidirectional variant with same VWM (12 V), symmetric clamping in both polarities; VBR min/max identical but ID doubled for VWM ≤ 10 V (not applicable here). | Required where AC-coupled signals or differential bus lines (e.g., RS-485) need protection without polarity constraints. | Select SMBJ12CA only if bidirectional clamping is mandated; SMBJ12A/54 offers lower cost and simpler layout for DC rail protection. |
| SMAJ12A | Same electrical specs but in smaller SMA (DO-214AC) package; 400 W PPPM rating (vs. 600 W), 22.5 V VC at 22.5 A IPPM. | Acceptable for lower-energy transients (IEC 61000-4-2 ±8 kV contact, not Level 4 surge); limited thermal mass reduces surge endurance. | Choose SMAJ12A only for space-constrained consumer designs with verified <400 W surge exposure; SMBJ12A/54 provides 50% higher energy margin. |
Compared with SMBJ12CA and SMAJ12A, SMBJ12A/54 delivers superior unidirectional surge handling (600 W), tighter clamping (19.9 V), and proven robustness in automotive and industrial environments - making it the preferred choice for mission-critical 12 V rail protection where layout allows SMB footprint.
Availability
SMBJ12A/54 is available at Aetrix Electronics and suitable for automotive body electronics, industrial PLC I/O modules, telecom power supplies, and appliance motor control systems requiring stable component supply with full traceability and long-term lifecycle support.
Supply support for SMBJ12A/54 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, precision, and automotive qualification.
The SMBJ series was engineered specifically for high-energy transient suppression in harsh environments - targeting automotive, industrial, and telecom applications where failure modes must be mitigated without compromising signal integrity or thermal performance.
FAQ
What is the maximum clamping voltage of SMBJ12A/54 under a 10/1000 µs surge?
The SMBJ12A/54 exhibits 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 at the device terminals under specified test conditions (TA = 25 °C, mounted on 0.2" × 0.2" copper pads) and defines the upper voltage limit imposed on the protected circuit during transient events. Designers use this parameter to verify that downstream components remain within their absolute maximum ratings during surge conditions.
Is SMBJ12A/54 suitable for automotive applications?
SMBJ12A/54 itself is a commercial-grade part, but Vishay offers AEC-Q101 qualified variants under ordering codes such as SMBJ12AHE3_B/H or SMBJ12AHM3_B/I. These versions undergo extended reliability testing including temperature cycling, humidity bias, and surge endurance validation per AEC-Q101. For automotive body electronics or infotainment power rails, specify the HE3 or HM3 suffix to ensure compliance; the base SMBJ12A/54 should be used only in non-automotive industrial or consumer applications unless fully validated per customer qualification protocols.
How does SMBJ12A/54 differ from SMBJ12A-E3?
SMBJ12A/54 denotes a specific tape-and-reel packaging configuration - "/54" indicates 7" diameter plastic tape and reel with 750 units per reel, per Vishay's ordering convention. SMBJ12A-E3 refers to the RoHS-compliant, commercial-grade version with matte tin-plated leads, while SMBJ12A/54 may use E3, M3, HE3, or HM3 base variants depending on the full ordering code. The "/54" suffix does not alter electrical or thermal specifications; it solely identifies packaging and quantity - ensuring correct logistics and SMT line feed compatibility.
What is the reverse leakage current of SMBJ12A/54 at its stand-off voltage?
The SMBJ12A/54 has a maximum reverse leakage current (ID) of 5.0 µA when biased at its rated stand-off voltage (VWM) of 12 V and tested at TA = 25 °C. This low leakage ensures minimal power loss in always-on circuits and avoids false triggering in high-impedance monitoring nodes. At elevated temperatures (e.g., 85 °C), leakage increases predictably per datasheet curves but remains below 50 µA - well within acceptable limits for most 12 V system supervision functions.
Can SMBJ12A/54 be used in bidirectional signal line protection?
No - SMBJ12A/54 is a unidirectional TVS diode, meaning it clamps only in reverse bias and conducts forward current like a standard diode when polarity is reversed. For bidirectional signal lines such as RS-485, USB, or Ethernet PHY interfaces, the bidirectional variant SMBJ12CA must be used instead. Attempting to use SMBJ12A/54 on AC-coupled or polarity-agnostic lines risks forward conduction during negative half-cycles, leading to excessive power dissipation, thermal runaway, or signal distortion.
SMBJ12A/54 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/54 FAQ
1.How can I place an order for SMBJ12A/54 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMBJ12A/54 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/54 reliable?
The price and inventory of SMBJ12A/54 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMBJ12A/54 is usually 5 days.
3.What payment methods are accepted for SMBJ12A/54?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMBJ12A/54 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMBJ12A/54?
SMBJ12A/54 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMBJ12A/54 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/54?
For technical support, including SMBJ12A/54 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMBJ12A/54 requirements.
6.How does Aetrix verify that SMBJ12A/54 is sourced from the original manufacturer or authorized distributors?
All SMBJ12A/54 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/54 meets industry standards.
7.What is the process for return or replacement of SMBJ12A/54?
All SMBJ12A/54 units undergo pre-shipment inspection (PSI). If there is an issue with SMBJ12A/54, 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/54 part is unused and in its original packaging.
Return procedure for SMBJ12A/54:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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