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STMicroelectronics SMBJ154A-TR
- Part No.:
- SMBJ154A-TR
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SMBJ154A-TR.pdf
- Description:
- TVS DIODE 154VWM 246VC SMB
- Quantity:
- Payment:
- Shipping:
Inventory:5,940
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Product details
Overview
SMBJ154A-TR from STMicroelectronics is a unidirectional transient voltage suppression (TVS) diode designed for primary-level surge protection on DC power rails and signal lines. It features a 154 V stand-off voltage (VRM), 246 V clamping voltage at 2.4 A (10/1000 µs), 600 W peak pulse power rating, and operates up to 150 °C junction temperature - deployed in industrial power supplies and telecom interface circuits.
For engineers reviewing the SMBJ154A-TR datasheet, SMBJ154A-TR pinout, SMBJ154A-TR application, or SMBJ154A-TR equivalent, key selection criteria include clamping performance under 10/1000 µs surges, low leakage (<0.2 µA at 25 °C), UL497B recognition for isolated loop circuits, and SMB package thermal robustness in high-reliability 24–48 V systems.
Technical Context
This TVS diode uses planar silicon technology to achieve stable breakdown behavior and low dynamic resistance (10.2 Ω at 8/20 µs). Its unidirectional configuration provides asymmetric clamping-forward conduction only during reverse overvoltage events-making it suitable for polarity-sensitive DC inputs like PoE injectors and PLC analog I/O modules.
The device complies with IEC 61000-4-2 (±30 kV contact/air discharge) and IEC 61000-4-4 Level 4 (4 kV), with failure mode typically short-circuit under overstress. Thermal derating follows a defined curve: peak power drops from 600 W at 25 °C to 350 W at 150 °C junction temperature.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Stand-off Voltage (VRM) | 154 V - maximum continuous reverse operating voltage before clamping initiates |
| Breakdown Voltage (VBR) | 171–180 V at 1 mA - precise threshold where avalanche conduction begins |
| Clamping Voltage (VCL) | 246 V at 2.4 A (10/1000 µs) - limits transient voltage seen by downstream ICs |
| Peak Pulse Power (PPP) | 600 W (10/1000 µs) - energy-handling capability for common lightning-induced surges |
| Leakage Current (IRM) | 0.2 µA max at 25 °C - ensures minimal standby power loss in always-on systems |
| Junction Temperature (Tj) | −55 to +150 °C - supports operation in enclosed industrial enclosures without forced cooling |
| Dynamic Resistance (RD) | 10.2 Ω - determines voltage overshoot during fast-rising transients (e.g., 8/20 µs) |
Pinout & Package
Package: SMB (DO-214AA), surface-mount, 2-terminal device with matte tin-plated leads compliant with J-STD-020 MSL Level 1 and IPC7531 footprint.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (Marked Band) | Surge Return Path | Connected to system ground or low-impedance return; conducts avalanche current during overvoltage |
| Anode | Protected Line Input | Connected to DC input or signal line; blocks reverse current until clamping threshold is exceeded |
Key Features
| Feature | Design Value |
|---|---|
| UL497B Recognition | Agency file E136224 - certified for use as isolated loop circuit protector in safety-critical telecom and process control systems |
| Low-Temperature Leakage | ≤0.2 µA at 25 °C - preserves signal integrity in high-impedance sensor front-ends and precision ADC references |
| High-Temperature Derating | 350 W sustained at Tj = 150 °C - enables reliable operation in sealed power converters without heatsinking |
| Fast Response Time | <1 ns - clamps transients before sensitive MOSFET gates or microcontroller I/O pins experience damage |
| IEC 61000-4-2 Compliance | ±30 kV air/contact discharge - meets highest ESD immunity level for industrial field equipment |
Applications
| Industrial PLC Analog Inputs | 48 V Telecom Power Feeds |
|---|---|
Use Scenario: Protection of 4–20 mA current-loop inputs against induced surges from nearby motor switching or lightning coupling. IC Role / Device Role / Timing Role: Primary clamping element placed between terminal block and op-amp input stage; absorbs >95% of 1 kV/500 A surge energy. Use Value: Prevents op-amp saturation and ADC offset drift caused by transient-induced rail collapse, maintaining measurement accuracy over 10+ year deployments. | Use Scenario: Surge suppression on -48 V DC distribution bus feeding remote radio units in cellular base stations. IC Role / Device Role / Timing Role: Unidirectional TVS connected cathode-to-ground on each feed line; clamps negative-going transients while blocking normal forward bias. Use Value: Limits bus voltage excursion to ≤246 V during 4 kV IEC 61000-4-4 bursts, preventing latch-up in downstream DC/DC controllers. |
| PoE++ (IEEE 802.3bt) Injectors | Smart Grid RTU Power Inputs |
Use Scenario: Input-side protection on 57 V PoE++ power sourcing equipment before the PD controller and isolation transformer. IC Role / Device Role / Timing Role: First-line defense against cable discharge events and hot-swap transients; placed upstream of active rectification. Use Value: Withstands repeated 10/1000 µs surges up to 600 W without degradation, ensuring injector uptime in multi-drop Ethernet deployments. | Use Scenario: DC input protection for remote terminal units installed in outdoor substations exposed to direct lightning induction. IC Role / Device Role / Timing Role: Mounted across 24 V or 48 V backup battery inputs; rated for continuous operation at 85 °C ambient with full derating margin. Use Value: Maintains <0.2 µA leakage at elevated temperatures, eliminating battery drain concerns in solar-charged backup systems. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ154CA-TR | Bidirectional version; symmetrical clamping (±246 V); higher capacitance (~100 pF at 0 V) | Required for AC-coupled or dual-polarity signal lines (e.g., RS-485, CAN FD) | Select when protecting bidirectional interfaces or where reverse polarity events must be suppressed |
| SMLJ154A | Same electrical specs but in larger SMC (DO-214AB) package; 1500 W peak power rating | Used where higher surge margin is needed (e.g., outdoor metering, railway signaling) | Choose when PCB layout allows larger footprint and system requires >600 W surge headroom |
Compared with SMBJ154CA-TR, SMBJ154A-TR offers lower capacitance and simpler biasing for DC rails; versus SMLJ154A, it trades peak power for space-constrained designs where 600 W suffices and thermal mass is limited.
Availability
SMBJ154A-TR is available at Aetrix Electronics and suitable for industrial automation, telecom infrastructure, and smart grid applications requiring stable component supply, long-term lifecycle support, and UL-recognized surge protection.
Supply support for SMBJ154A-TR 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
STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, delivering intelligent power, sensing, and control solutions across automotive, industrial, and consumer markets.
The SMBJ series belongs to ST's Transient Voltage Suppressor portfolio, engineered specifically for robust, standards-compliant overvoltage protection in harsh electromagnetic environments - targeting reliability-critical power and interface circuits.
FAQ
What is the maximum clamping voltage of SMBJ154A-TR under a 10/1000 µs surge?
The maximum clamping voltage is 246 V at 2.4 A for a 10/1000 µs waveform, measured at 25 °C ambient. This value increases linearly with junction temperature using the αT coefficient of 10.8 × 10⁻⁴/°C, reaching ~265 V at 150 °C junction temperature.
Does SMBJ154A-TR meet UL497B requirements for isolated loop protection?
Yes - it is recognized to UL497B as an isolated loop circuit protector under agency file number E136224, covering both unidirectional and bidirectional variants. This certification validates its use in safety-isolated signal and power loops per ANSI/UL standards.
How does SMBJ154A-TR differ from SMBJ154CA-TR in circuit implementation?
SMBJ154A-TR is unidirectional and must be oriented with cathode toward ground to protect positive-going transients on DC lines. SMBJ154CA-TR is bidirectional and symmetrically clamps both polarities, making it suitable for AC signals or systems where reverse polarity faults occur - requiring no orientation-dependent placement.
Can SMBJ154A-TR be used in parallel for higher surge current handling?
No - paralleling TVS diodes is not recommended due to mismatched breakdown voltages causing current imbalance and premature failure. For higher current capability, select a single device with higher PPP rating (e.g., SMLJ154A) or implement staged protection with MOVs and gas discharge tubes upstream.
SMBJ154A-TR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- DO-214AA, SMB
- Series:
- SMBJ, TRANSIL™
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 154V
- Voltage - Breakdown (Min):
- 171V
- Voltage - Clamping (Max) @ Ipp:
- 246V
- Current - Peak Pulse (10/1000µs):
- 2.4A
- 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:
- SMB
SMBJ154A-TR FAQ
1.How can I place an order for SMBJ154A-TR through Aetrix?
Please submit a Request for Quotation (RFQ) for SMBJ154A-TR 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 SMBJ154A-TR reliable?
The price and inventory of SMBJ154A-TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMBJ154A-TR is usually 5 days.
3.What payment methods are accepted for SMBJ154A-TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMBJ154A-TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMBJ154A-TR?
SMBJ154A-TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMBJ154A-TR 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 SMBJ154A-TR?
For technical support, including SMBJ154A-TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMBJ154A-TR requirements.
6.How does Aetrix verify that SMBJ154A-TR is sourced from the original manufacturer or authorized distributors?
All SMBJ154A-TR 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 SMBJ154A-TR meets industry standards.
7.What is the process for return or replacement of SMBJ154A-TR?
All SMBJ154A-TR units undergo pre-shipment inspection (PSI). If there is an issue with SMBJ154A-TR, 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 SMBJ154A-TR part is unused and in its original packaging.
Return procedure for SMBJ154A-TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMBJ154A-TR Tags
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