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onsemi SMBJ12A933
- Part No.:
- SMBJ12A933
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SMBJ12A933.pdf
- Description:
- TVS DIODE 12VWM 19.9VC DO214AA
- Quantity:
- Payment:
- Shipping:
Inventory:4,047
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Product details
Overview
SMBJ12A from Taiwan Semiconductor is a unidirectional 600W surface-mount transient voltage suppressor (TVS) diode in DO-214AA (SMB) package, designed for clamping ESD and surge transients in power rails and signal lines. It features a 12V working stand-off voltage (VWM), 13.3–14.7V breakdown voltage (VBR), and clamps to ≤19.9V at 31A peak impulse current (IPP), making it suitable for protecting 12V automotive and industrial control circuits.
For engineers reviewing the SMBJ12A datasheet, pinout, applications, or equivalent options, key selection criteria include clamping voltage margin relative to system rail tolerance, leakage current at operating voltage, thermal derating above 25°C, and compliance with ISO 7637-2 Pulse 1/2a/2b/3a/3b for automotive load-dump and inductive-switching immunity.
Technical Context
The SMBJ12A uses a glass-passivated silicon junction optimized for fast response (<1.0 ps) and low clamping ratio (VC/VBR ≈ 1.42). Its unidirectional configuration provides forward conduction capability with VF = 3.5V at 50A, enabling use in DC power line protection where reverse polarity is not expected.
Thermal performance is defined by RθJA = 55°C/W and RθJC = 10°C/W, supporting continuous operation up to TJ = 150°C when mounted on adequate copper area. The device meets JESD201 Class 2 whisker resistance and J-STD-020 Level 1 moisture sensitivity requirements.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 12 V - Maximum continuous DC or RMS voltage the device blocks without significant leakage |
| VBR min/max | 13.3 V / 14.7 V - Breakdown occurs within this range at 1 mA test current; defines minimum overvoltage threshold |
| VC @ IPP | 19.9 V @ 31 A - Clamped voltage during 10/1000 µs surge; must stay below protected IC's absolute max rating |
| ID @ VWM | <1 µA - Leakage current at 12 V ensures negligible standby power loss in battery-powered systems |
| PPK | 600 W - Peak pulse power handling per single 10/1000 µs transient; derates linearly above 25°C ambient |
| TJ max | +150 °C - Maximum junction temperature; requires thermal design to limit steady-state power dissipation to 3 W |
| Package | DO-214AA (SMB) - Standard surface-mount outline with cathode band marking; compatible with automated placement |
Pinout & Package
DO-214AA (SMB) package: molded plastic case with matte tin-plated leads, polarity indicated by cathode band. Weight ≈ 0.090 g. Meets UL 94V-0 flammability rating.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Low-side reference terminal | Connected to ground or return path; forms clamping path when cathode is at higher potential |
| Cathode | High-side transient input terminal | Connected to protected line (e.g., 12V rail); conducts surge current to anode during overvoltage |
Key Features
| Feature | Design Value |
|---|---|
| Clamping ratio (VC/VBR) | ≤1.42 - Ensures tight voltage limiting with minimal headroom above breakdown, critical for 12V system margin |
| Response time | <1.0 ps - Faster than most ESD events, enabling effective suppression before downstream IC damage |
| ISO 7637-2 compliance | Pulse 1/2a/2b/3a/3b - Validated for automotive electronics immunity testing, including load dump and inductive switching |
| Moisture sensitivity | Level 1 per J-STD-020 - No bake requirement prior to reflow; supports standard SMT assembly flow |
| RoHS & halogen-free | Compliant per IEC 61249-2-21 - Meets environmental regulations for industrial and automotive end equipment |
Applications
| Automotive Power Rail Protection | Industrial PLC Input Protection |
|---|---|
Use Scenario: Protecting 12V supply lines in body control modules against load-dump transients (ISO 7637-2 Pulse 5a). IC Role / Device Role / Timing Role: Unidirectional TVS placed between 12V rail and chassis ground to clamp surges exceeding 35V. Use Value: Limits clamped voltage to 19.9V, preserving integrity of 30V-rated DC-DC converters and microcontrollers. |
Use Scenario: Safeguarding digital input channels of programmable logic controllers exposed to inductive kickback from solenoid drivers. IC Role / Device Role / Timing Role: TVS connected across input terminals to shunt fast-rising transients (Pulse 1/3b) before reaching optocoupler inputs. Use Value: Sub-1µA leakage at 12V prevents false triggering; 31A IPP handles worst-case 500V/50Ω transients. |
| LED Driver Overvoltage Clamp | USB Port ESD Protection |
Use Scenario: Preventing overvoltage failure in constant-current LED drivers subjected to hot-swap or cable discharge events. IC Role / Device Role / Timing Role: Placed across driver output to clamp transients induced by long wiring harnesses or connector mating. Use Value: 19.9V clamping ensures LED string remains within safe forward-voltage window; glass passivation enables stable long-term reliability. |
Use Scenario: Secondary-level ESD protection on USB VBUS line in embedded host devices operating from 12V adapters. IC Role / Device Role / Timing Role: Unidirectional TVS between VBUS and ground, upstream of USB power switch IC. Use Value: 12V VWM allows normal 5V operation with margin; <1µA leakage avoids adapter quiescent current increase. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| Littelfuse SMAJ12A | Same DO-214AC (SMA) package; slightly higher VC = 20.1V @ 30.2A; RθJA = 65°C/W | Lower power density due to larger thermal resistance; less suitable for high-ambient industrial enclosures | Prefer SMBJ12A where PCB space is constrained and thermal management is limited |
| ON Semiconductor 1.5SMC12A | DO-214AB (SMC) package; higher PPK = 1500W; VC = 19.9V @ 75.4A; VBR = 13.3–14.7V identical | Overqualified for 600W needs; larger footprint and higher cost; better for extreme surge environments | Select SMBJ12A when 600W rating and SMB footprint are sufficient and board area is premium |
Compared with SMAJ12A and 1.5SMC12A, SMBJ12A delivers optimal balance of compact DO-214AA size, verified 600W surge capability, and thermal performance (RθJA = 55°C/W), making it ideal for space-constrained 12V systems requiring ISO 7637-2 compliance without over-engineering.
Availability
SMBJ12A is available at Aetrix Electronics and suitable for automotive body electronics, industrial PLC I/O modules, LED lighting drivers, and USB power interface designs requiring stable component supply and full traceability.
Supply support for SMBJ12A 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
Taiwan Semiconductor Corporation (TSC) is a vertically integrated analog and discrete semiconductor manufacturer headquartered in Hsinchu, Taiwan, specializing in TVS diodes, rectifiers, MOSFETs, and power management components.
The SMBJ series was developed specifically for robust, surface-mount transient suppression in automotive and industrial environments, emphasizing ISO 7637-2 compliance, low clamping ratio, and high-reliability packaging.
FAQ
What is the maximum clamping voltage of SMBJ12A under standard test conditions?
The SMBJ12A has a maximum clamping voltage (VC) of 19.9 V when subjected to a 10/1000 µs surge waveform at 31 A peak impulse current (IPP), measured per ANSI/IEEE C62.35. This value is guaranteed across the full operating temperature range and defines the upper voltage limit imposed on protected circuitry during transient events.
Is SMBJ12A suitable for bidirectional transient protection?
No, SMBJ12A is a unidirectional TVS diode and is not rated for bidirectional operation. For bipolar applications, Taiwan Semiconductor specifies parts with "C" or "CA" suffixes (e.g., SMBJ12CA). Using SMBJ12A in reverse-biased configurations may result in premature failure due to lack of specified reverse breakdown characteristics.
What is the forward voltage drop of SMBJ12A at high surge current?
The SMBJ12A exhibits a forward voltage (VF) of 3.5 V at 50 A DC forward surge current, as specified in the Absolute Maximum Ratings table. This parameter applies only during unidirectional conduction and is relevant for evaluating voltage drop in DC power line protection scenarios during sustained overcurrent events.
Does SMBJ12A require special handling during PCB assembly?
No - SMBJ12A is rated at Moisture Sensitivity Level 1 per J-STD-020 and does not require dry-packaging or baking prior to reflow soldering. Its DO-214AA (SMB) package is compatible with standard lead-free reflow profiles, and matte tin-plated leads ensure reliable solderability per J-STD-002.
How does SMBJ12A compare to SMBJ12 in terms of clamping performance?
SMBJ12A offers tighter VBR tolerance (13.3–14.7 V vs. 13.3–16.3 V for SMBJ12) and lower clamping voltage (19.9 V vs. 22.0 V at rated IPP), resulting in improved protection margin for 12V systems. Both share identical package, power rating, and thermal specs, but SMBJ12A is preferred where precise clamping control is required.
SMBJ12A933 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Package/Case:
- DO-214AA, SMB
- Series:
- SMBJ
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- 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 (SMB)
SMBJ12A933 FAQ
1.How can I place an order for SMBJ12A933 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMBJ12A933 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 SMBJ12A933 reliable?
The price and inventory of SMBJ12A933 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMBJ12A933 is usually 5 days.
3.What payment methods are accepted for SMBJ12A933?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMBJ12A933 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMBJ12A933?
SMBJ12A933 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMBJ12A933 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 SMBJ12A933?
For technical support, including SMBJ12A933 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMBJ12A933 requirements.
6.How does Aetrix verify that SMBJ12A933 is sourced from the original manufacturer or authorized distributors?
All SMBJ12A933 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 SMBJ12A933 meets industry standards.
7.What is the process for return or replacement of SMBJ12A933?
All SMBJ12A933 units undergo pre-shipment inspection (PSI). If there is an issue with SMBJ12A933, 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 SMBJ12A933 part is unused and in its original packaging.
Return procedure for SMBJ12A933:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMBJ12A933 Tags
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onsemi
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