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STMicroelectronics SMBJ48A-TR
- Part No.:
- SMBJ48A-TR
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SMBJ48A-TR.pdf
- Description:
- TVS DIODE 48VWM 77.4VC SMB
- Quantity:
- Payment:
- Shipping:
Inventory:10,582
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Product details
Overview
SMBJ48A-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 delivers 600 W peak pulse power (10/1000 µs), clamps transients to 77.4 V at 8.1 A, and maintains low leakage (0.2 µA @ 25 °C) while operating up to 150 °C junction temperature - deployed in industrial power supplies and automotive body control modules.
For engineers reviewing the SMBJ48A-TR datasheet, SMBJ48A-TR pinout, SMBJ48A-TR application, or SMBJ48A-TR equivalent, key selection criteria include standoff voltage (48 V), clamping voltage (77.4 V), peak pulse current (8.1 A), thermal derating behavior above 25 °C, and UL497B recognition for isolated loop circuit protection.
Technical Context
This TVS diode uses planar silicon junction technology to achieve stable breakdown characteristics and low dynamic resistance (2.28 Ω at 8/20 µs). Its unidirectional configuration enables asymmetric clamping - forward conduction only during reverse-polarity surges - making it suitable for polarity-sensitive DC inputs.
The device meets IEC 61000-4-2 level 4 (±30 kV contact/air discharge) and IEC 61000-4-4 level 4 (4 kV), with clamping voltage defined at 10/1000 µs and 8/20 µs waveforms. Thermal performance is validated per JEDEC JESD22-A104 and derated linearly above 25 °C using αT = 10.3 × 10−4/°C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Standoff Voltage (VRWM) | 48 V - Maximum continuous DC operating voltage before leakage exceeds 1 µA at 85 °C. |
| Breakdown Voltage (VBR) | 53.3–56.1 V @ 1 mA - Confirmed voltage range where device enters avalanche conduction under controlled test conditions. |
| Clamping Voltage (VCL) | 77.4 V @ 8.1 A (10/1000 µs) - Peak voltage seen by protected circuit during worst-case surge event. |
| Peak Pulse Power (PPP) | 600 W (10/1000 µs) - Sustained surge energy handling capability at Tj = 25 °C; derates to 350 W at Tj = 150 °C. |
| Leakage Current (IR) | 0.2 µA @ 25 °C, 1 µA @ 85 °C - Ensures minimal standby power loss and signal integrity in high-impedance circuits. |
| Dynamic Resistance (RD) | 2.28 Ω (10/1000 µs) - Determines voltage overshoot during fast-rising transients; lower RD improves clamping fidelity. |
| Operating Junction Temp. | −55 to +150 °C - Enables deployment in under-hood automotive, industrial SMPS, and outdoor telecom equipment. |
Pinout & Package
Package: SMB (DO-214AA), surface-mount, matte tin-plated leads compliant with J-STD-020 MSL Level 1 and IPC-7531 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 events. |
| Anode | Protected Line Input | Connected to line being protected (e.g., +48 V rail); blocks normal operation but conducts when VAK > VBR. |
Key Features
| Feature | Design Value |
|---|---|
| UL497B Recognition | Agency file E136224 - Validated for use as isolated loop circuit protector in safety-critical industrial and telecom systems. |
| Low-Temperature Leakage Stability | 0.2 µA max @ 25 °C - Minimizes false triggering and power drain in battery-backed or low-power sensor nodes. |
| High-Temperature Derating | 350 W PPP @ Tj = 150 °C - Maintains robust surge margin in thermally constrained enclosures without forced cooling. |
| Fast Response Time | < 1 ns - Limits voltage overshoot during nanosecond-scale ESD events (IEC 61000-4-2) before downstream ICs are damaged. |
| JEDEC-Compliant SMB Outline | Standardized mechanical dimensions (EIA-481 tape/reel, 2.5 mm pitch) - Ensures compatibility with automated SMT placement and reflow profiles. |
Applications
| Industrial Power Supply Input Protection | Automotive Body Control Module (BCM) CAN Bus Line Protection |
|---|---|
|
Use Scenario: 48 V DC input stage of programmable logic controller (PLC) power supply exposed to load dump and inductive switching transients. IC Role / Device Role / Timing Role: Primary clamping element placed between input rail and ground, absorbing up to 600 W surges before downstream DC-DC converters. Use Value: Prevents catastrophic failure of upstream rectifiers and downstream regulators by limiting transient voltage to ≤77.4 V during 10/1000 µs events. |
Use Scenario: Protection of 12 V auxiliary power rail feeding CAN transceivers in vehicle BCM units subject to ISO 7637-2 pulses. IC Role / Device Role / Timing Role: Unidirectional TVS placed across VCC and GND to suppress coupled transients from relay coils and motor drivers. Use Value: Maintains CAN bus uptime by preventing latch-up or burnout of transceivers during 100 V/50 ms load-dump events. |
| Telecom Remote Radio Unit (RRU) DC Feeder Protection | Smart Meter Battery Backup Circuit Protection |
|
Use Scenario: Outdoor 48 V PoE-like DC feeder line powering remote radio units, exposed to lightning-induced surges on long cable runs. IC Role / Device Role / Timing Role: First-stage surge limiter mounted at RRU enclosure entry point, coordinated with secondary MOV/GDT stages. Use Value: Clamps induced surges to safe levels (<77.4 V) within 1 ns, preserving RF front-end LNA and ADC integrity. |
Use Scenario: 3.6 V lithium-thionyl chloride backup battery circuit in utility smart meters, requiring ultra-low leakage to extend 15-year service life. IC Role / Device Role / Timing Role: Standby-mode TVS across battery terminals to block reverse polarity connection and ESD during field servicing. Use Value: Enables 15+ year operation by limiting leakage to 0.2 µA at 25 °C - reducing annual battery self-discharge by <0.1%. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ48CA-TR | Bidirectional version; symmetric clamping (±77.4 V); same VRWM, VBR, and PPP. | Required for AC-coupled or dual-polarity signal lines (e.g., RS-485, USB D+/D−), not DC rails. | Select SMBJ48CA-TR only when protecting bidirectional signals or floating references - avoid on unidirectional DC supplies due to unnecessary forward conduction path. |
| SMAJ48A-TR | Lower PPP (400 W @ 10/1000 µs); higher VCL (83 V @ 6.2 A); same SMB package but reduced surge margin. | Suitable for cost-sensitive consumer electronics with lower surge exposure (e.g., set-top boxes), not industrial-grade 600 W requirements. | Choose SMAJ48A-TR only if system-level testing confirms 400 W surge immunity is sufficient - verify clamping headroom against downstream IC absolute maximum ratings. |
Compared with SMBJ48CA-TR, SMBJ48A-TR provides tighter clamping on DC rails and avoids forward conduction during normal operation; versus SMAJ48A-TR, it delivers 50% higher surge energy handling and 5.6 V lower clamping voltage - critical for protecting 50 V-rated MOSFETs and controllers.
Availability
SMBJ48A-TR is available at Aetrix Electronics and suitable for industrial power supplies, automotive body control modules, telecom remote radio units, and smart meter battery backup circuits requiring stable component supply across multi-year production cycles.
Supply support for SMBJ48A-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 silicon solutions for automotive, industrial, and power management applications.
The SMBJ series belongs to ST's high-reliability TVS portfolio, engineered specifically for robust transient suppression in harsh environments - emphasizing low leakage, high-temperature stability, and standards-compliant surge immunity.
FAQ
What is the maximum allowable surge current for SMBJ48A-TR under IEC 61000-4-4 conditions?
The SMBJ48A-TR sustains 8.1 A peak pulse current (IPP) at 77.4 V clamping voltage for 10/1000 µs waveform and 100 A for 8/20 µs waveform. These values are measured per IEC 61000-4-4 level 4 (4 kV) and validated in ST's DS1283 Rev 14, Table 2.
Does SMBJ48A-TR require heatsinking in standard PCB layouts?
No external heatsink is required. With Rth(j-a) ≈ 120 °C/W on a 1 cm² copper pad per lead (per Figure 12), the device stays within 150 °C junction limit during single 600 W surges. Continuous power dissipation remains negligible due to its transient-only operation.
How does SMBJ48A-TR differ from SMBJ48CA-TR in physical marking and orientation?
SMBJ48A-TR is marked "BUW" (per Table 6), with cathode band indicating polarity; SMBJ48CA-TR is marked "BBW" and has no polarity - both use identical SMB packages and tape/reel orientation per Figure 16, but BUW must be oriented with band toward ground.
Is SMBJ48A-TR compatible with lead-free reflow processes?
Yes. It complies with J-STD-020 MSL Level 1 and supports ST's recommended Pb-free reflow profile (peak 240–245 °C, 60–90 sec above 220 °C), verified per Figure 22 in DS1283 Rev 14 and qualified to JEDEC JESD22-A113.
SMBJ48A-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):
- 48V
- Voltage - Breakdown (Min):
- 53.3V
- Voltage - Clamping (Max) @ Ipp:
- 77.4V
- Current - Peak Pulse (10/1000µs):
- 8.1A
- 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
SMBJ48A-TR FAQ
1.How can I place an order for SMBJ48A-TR through Aetrix?
Please submit a Request for Quotation (RFQ) for SMBJ48A-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 SMBJ48A-TR reliable?
The price and inventory of SMBJ48A-TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMBJ48A-TR is usually 5 days.
3.What payment methods are accepted for SMBJ48A-TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMBJ48A-TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMBJ48A-TR?
SMBJ48A-TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMBJ48A-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 SMBJ48A-TR?
For technical support, including SMBJ48A-TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMBJ48A-TR requirements.
6.How does Aetrix verify that SMBJ48A-TR is sourced from the original manufacturer or authorized distributors?
All SMBJ48A-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 SMBJ48A-TR meets industry standards.
7.What is the process for return or replacement of SMBJ48A-TR?
All SMBJ48A-TR units undergo pre-shipment inspection (PSI). If there is an issue with SMBJ48A-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 SMBJ48A-TR part is unused and in its original packaging.
Return procedure for SMBJ48A-TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMBJ48A-TR Tags
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ESD9B5.0ST5G
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Diodes Incorporated
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Diodes Incorporated
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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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