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onsemi SMBJ12AONT3
- Part No.:
- SMBJ12AONT3
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SMBJ12AONT3.pdf
- Description:
- TVS DIODE 12VWM 19.9VC SMB
- Quantity:
- Payment:
- Shipping:
Inventory:7,366
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Product details
Overview
SMBJ12AONT3 from onsemi is a unidirectional 600 W transient voltage suppressor (TVS) diode designed for parallel overvoltage protection of sensitive electronics. It features a 12 V working peak reverse voltage (VRWM), 19.9 V clamping voltage at 30.2 A peak pulse current, <1 ns response time, and UL 497B recognition for isolated loop circuit protection-used in automotive power supplies and industrial communication interfaces.
For engineers reviewing the SMBJ12AONT3 datasheet, pinout, applications, or equivalent options, key selection criteria include clamping performance under 10/1000 µs transients, ESD robustness (>16 kV HBM), thermal derating above 75°C, and Pb-free SMB package compatibility with automated SMT assembly.
Technical Context
The SMBJ12AONT3 operates as a Zener-based unidirectional TVS, conducting only during positive transients relative to its cathode. Its breakdown voltage is specified at 13.2–14.3 V (min–max) with 1 mA test current, and it clamps to ≤19.9 V when subjected to a 30.2 A 10/1000 µs surge pulse.
Thermal design relies on junction-to-lead resistance of 40 °C/W and junction-to-ambient resistance of 226 °C/W on FR-4 board with minimum footprint. Derating begins at 75°C for power dissipation and at 25°C for ambient-rated operation, supporting use in enclosed industrial enclosures with limited airflow.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Working Peak Reverse Voltage (VRWM) | 12 V - Maximum continuous reverse voltage before significant leakage; defines operating margin below clamping threshold. |
| Clamping Voltage (VC) | 19.9 V @ 30.2 A - Peak voltage seen by protected circuit during worst-case 10/1000 µs surge; determines downstream component stress. |
| Peak Pulse Power (PPK) | 600 W @ 1 ms - Surge energy handling capacity; validates protection against IEC 61000-4-5 Level 4 surges. |
| Reverse Leakage Current | <5 µA @ 12 V - Minimal standby power loss and signal integrity impact in high-impedance circuits. |
| Response Time | <1 ns - Enables suppression before transient propagates beyond local node; critical for fast-edge digital interfaces. |
| ESD Rating (HBM) | >16 kV - Meets IEC 61000-4-2 Level 4; protects against human-body discharge events without degradation. |
| UL Recognition | UL 497B QVGV2 - Certified for isolated loop circuit protection; satisfies safety requirements for telecom and medical auxiliary power. |
Pinout & Package
Package: SMB (Case 403A), surface-mount, Pb-free, cathode-indicated by band. Dimensions: 4.06–4.60 mm length × 3.30–3.95 mm width × 1.02–1.60 mm height. Mounting position: any; solderable leads with modified L-bend for enhanced pad adhesion.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Current entry terminal during forward conduction | Connected to ground or low-side reference; enables unidirectional clamping of positive transients on cathode side. |
| Cathode | Current exit terminal during reverse breakdown | Connected to protected line (e.g., 12 V rail); conducts surge current to ground when voltage exceeds VRWM. |
Key Features
| Feature | Design Value |
|---|---|
| Low zener impedance | Ensures stable clamping voltage across varying surge currents-critical for consistent protection in automotive load-dump scenarios. |
| High surge capability (600 W) | Withstands repeated 10/1000 µs transients up to 30.2 A without parametric shift-validated per IEC 61000-4-5. |
| Fast response time (<1 ns) | Minimizes voltage overshoot before clamping engages-essential for protecting high-speed CAN or RS-485 receivers. |
| UL 497B recognition | Confirms compliance for isolated loop protection in safety-critical systems such as medical sensor interfaces and industrial PLC I/O modules. |
| Pb-free construction | Meets RoHS Directive 2011/65/EU and JEDEC J-STD-020 moisture sensitivity level (MSL) 1-enables lead-free reflow without delamination. |
Applications
| Automotive Power Supply Protection | Industrial Communication Interface |
|---|---|
Use Scenario: Protecting 12 V battery-fed ECUs from load dump and alternator ripple transients. IC Role / Device Role / Timing Role: Unidirectional TVS placed between power rail and chassis ground to clamp positive surges above 12 V. Use Value: Limits peak voltage to 19.9 V during 30.2 A transients-prevents damage to downstream DC-DC controllers and microcontrollers. | Use Scenario: Shielding RS-485 transceivers in factory automation networks from EFT and surge coupling. IC Role / Device Role / Timing Role: Parallel-connected TVS on differential bus lines (A/B) referenced to common-mode ground. Use Value: Sub-1 ns response ensures clamping occurs before transceiver input stages exceed absolute maximum ratings. |
| Medical Equipment Power Input | Consumer Power Adapter Output |
Use Scenario: Safeguarding isolated 12 V auxiliary supplies in diagnostic imaging devices per IEC 60601-1. IC Role / Device Role / Timing Role: UL 497B-recognized TVS on secondary-side output to meet creepage/clearance and surge immunity requirements. Use Value: Validated isolation barrier protection reduces need for additional optocoupled monitoring or redundant clamping. | Use Scenario: Suppressing switching noise and lightning-induced surges on 12 V USB-C PD adapter outputs. IC Role / Device Role / Timing Role: Final-stage TVS on regulated output rail before connector interface. Use Value: 5 µA max leakage avoids loading regulation feedback networks; 600 W rating handles EN 61000-4-5 open-circuit surges. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ12AT3G | Same electrical specs; Pb-free marking uses "G" suffix instead of "ON" prefix; identical SMB package and thermal performance. | No functional difference; both qualified for automotive and industrial use per same AEC-Q200-relevant stress tests. | Select SMBJ12AT3G if distributor inventory favors ON Semiconductor's standardized "T3G" packaging nomenclature. |
| P6SMB12A | Identical VRWM (12 V), VC (19.9 V), and PPK (600 W); manufactured by STMicroelectronics; same SMB case outline but minor footprint tolerance differences. | Approved for consumer-grade applications; lacks UL 497B recognition-requires additional system-level validation for medical or telecom use. | Choose P6SMB12A where cost optimization is prioritized and UL certification is not mandated by end-equipment standards. |
Compared with SMBJ12AONT3, SMBJ12AT3G offers identical protection performance with alternate marking convention, while P6SMB12A provides equivalent surge handling but omits UL 497B-making SMBJ12AONT3 preferable for safety-certified designs requiring documented isolated-loop compliance.
Availability
SMBJ12AONT3 is available at Aetrix Electronics and suitable for automotive power supply protection, industrial communication interface hardening, and medical equipment power input conditioning requiring stable component supply and long-term lifecycle support.
Supply support for SMBJ12AONT3 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
onsemi (formerly ON Semiconductor) is a global semiconductor supplier focused on energy-efficient electronics, with leadership in automotive, industrial, cloud, and sensing solutions.
The SMBJ series was developed specifically for high-reliability transient suppression in harsh environments-targeting automotive subsystems, industrial control I/O, and medical auxiliary power where UL recognition and repeatable clamping are mandatory.
FAQ
What is the clamping voltage of SMBJ12AONT3 at its rated peak pulse current?
The SMBJ12AONT3 has a maximum clamping voltage (VC) of 19.9 V when subjected to a 30.2 A peak pulse current with a 10/1000 µs waveform. This value is measured per Figure 1 in the official onsemi datasheet and defines the upper voltage limit imposed on protected circuits during surge events. The SMBJ12AONT3 maintains this clamping performance across its full operating temperature range of –65°C to +150°C.
Is SMBJ12AONT3 certified for use in medical equipment power supplies?
Yes, SMBJ12AONT3 carries UL 497B recognition (File #116110, QVGV2 category) for isolated loop circuit protection-explicitly validated for medical auxiliary power applications per IEC 60601-1 requirements. This certification covers dielectric withstand, endurance conditioning, and strike voltage breakdown testing, distinguishing SMBJ12AONT3 from generic TVS diodes lacking third-party safety validation.
Does SMBJ12AONT3 support lead-free reflow soldering processes?
Yes, SMBJ12AONT3 is Pb-free and qualified for lead-free reflow per JEDEC J-STD-020. Its maximum soldering temperature is rated at 260°C for 10 seconds, compatible with standard SnAgCu (SAC305) profiles. The device's thermosetting plastic case and corrosion-resistant leads ensure reliable wetting and intermetallic formation without voiding or delamination during production assembly.
How does the SMBJ12AONT3 differ from bidirectional TVS diodes like SMBJ12CA?
The SMBJ12AONT3 is unidirectional and functions only during positive transients on its cathode terminal, whereas SMBJ12CA clamps both polarities. This makes SMBJ12AONT3 ideal for DC power rails where reverse voltage is blocked by upstream components, offering lower leakage (<5 µA @ 12 V) and tighter VBR distribution (13.2–14.3 V). SMBJ12AONT3 cannot replace SMBJ12CA in AC-coupled or bipolar signal lines.
What is the thermal resistance from junction to ambient for SMBJ12AONT3 on a standard FR-4 PCB?
The SMBJ12AONT3 has a junction-to-ambient thermal resistance (RJA) of 226 °C/W when mounted on an FR-4 board using onsemi's minimum recommended footprint (Case 403A outline). This value assumes no thermal vias or copper pour-designers must apply derating above 25°C ambient per the published curve, reducing allowable power dissipation by 4.4 mW/°C above that threshold.
SMBJ12AONT3 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):
- 13.2V
- Voltage - Clamping (Max) @ Ipp:
- 19.9V
- Current - Peak Pulse (10/1000µs):
- 30.2A (8/20µs)
- Power - Peak Pulse:
- 600W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -65°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMB
SMBJ12AONT3 FAQ
1.How can I place an order for SMBJ12AONT3 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMBJ12AONT3 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 SMBJ12AONT3 reliable?
The price and inventory of SMBJ12AONT3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMBJ12AONT3 is usually 5 days.
3.What payment methods are accepted for SMBJ12AONT3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMBJ12AONT3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMBJ12AONT3?
SMBJ12AONT3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMBJ12AONT3 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 SMBJ12AONT3?
For technical support, including SMBJ12AONT3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMBJ12AONT3 requirements.
6.How does Aetrix verify that SMBJ12AONT3 is sourced from the original manufacturer or authorized distributors?
All SMBJ12AONT3 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 SMBJ12AONT3 meets industry standards.
7.What is the process for return or replacement of SMBJ12AONT3?
All SMBJ12AONT3 units undergo pre-shipment inspection (PSI). If there is an issue with SMBJ12AONT3, 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 SMBJ12AONT3 part is unused and in its original packaging.
Return procedure for SMBJ12AONT3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMBJ12AONT3 Tags
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onsemi
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Diodes Incorporated
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onsemi
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Diodes Incorporated
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Diodes Incorporated
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onsemi
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Diodes Incorporated
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Diodes Incorporated
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Nexperia USA Inc.
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Toshiba Semiconductor and Storage
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Diodes Incorporated
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