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Taiwan Semiconductor Corporation SMBJ45
- Part No.:
- SMBJ45
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SMBJ45.pdf
- Description:
- 600W, 55.6V, 10%, UNIDIRECTIONAL
- Quantity:
- Payment:
- Shipping:
Inventory:7,750
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Product details
Overview
SMBJ45 from Taiwan Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode in DO-214AA (SMB) package, designed for high-energy ESD and surge protection in DC power lines and signal interfaces. It features a 45 V working stand-off voltage (VWM), 50.0–61.1 V breakdown voltage (VBR @ 1 mA), 80.3 V maximum clamping voltage (VC @ 7.8 A), 600 W peak pulse power (10/1000 µs), and <1 µA leakage at rated VWM, deployed in automotive lighting control and industrial sensor I/O protection.
For engineers reviewing the SMBJ45 datasheet, SMBJ45 pinout, SMBJ45 application, or SMBJ45 equivalent, key selection criteria include clamping performance under ISO 7637-2 Pulse 1/2a/2b/3a/3b, thermal derating above 25°C, unidirectional polarity marking, junction-to-ambient thermal resistance (55 °C/W), and compatibility with J-STD-002 solderability requirements.
Technical Context
The SMBJ45 operates as a silicon avalanche diode optimized for fast transient suppression, with sub-1 ps response time and glass-passivated junction ensuring stable breakdown characteristics. Its unidirectional configuration provides forward conduction only during reverse overvoltage events, enabling precise clamping on supply rails without forward-path interference.
Designed for surface-mount automation, it meets JESD201 Class 2 whisker resistance and J-STD-020 Moisture Sensitivity Level 1. Thermal performance is defined by RθJC = 10 °C/W and RθJA = 55 °C/W, supporting continuous operation up to TJ = 150 °C in PCB-constrained environments.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 45 V - Maximum continuous DC or RMS voltage the device blocks without conduction |
| VBR min/max | 50.0 V / 61.1 V @ 1 mA - Confirmed avalanche onset range defining reliable turn-on threshold |
| VC @ IPP | 80.3 V @ 7.8 A - Clamped voltage during 10/1000 µs surge, limiting downstream stress |
| PPK | 600 W - Peak non-repetitive surge power handling capability per standard waveform |
| ID @ VWM | <1 µA - Low leakage ensures minimal standby current draw in protected circuits |
| TJ max | 150 °C - Maximum junction temperature enabling use in under-hood or enclosed industrial enclosures |
| RθJA | 55 °C/W - Thermal resistance from junction to ambient, critical for board-level thermal design |
Pinout & Package
Package: DO-214AA (SMB), surface-mount, single-die unidirectional TVS diode with cathode band marking. Matte tin-plated leads, UL 94V-0 molding compound, 0.090 g typical weight.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal | Connected to lower-potential side (e.g., GND or return path); conducts during reverse transients |
| Cathode | Clamping reference terminal | Marked with band; connected to protected line (e.g., +45 V rail); defines clamping polarity |
Key Features
| Feature | Design Value |
|---|---|
| Fast response time | <1.0 ps - Enables suppression before sensitive ICs experience latch-up or gate oxide damage |
| Glass passivated junction | Stable VBR tolerance and long-term reliability under thermal cycling and humidity |
| ISO 7637-2 compliance | Validated for Pulse 1 (inductive load dump), Pulse 2a/2b (battery disconnect), Pulse 3a/3b (switching noise) |
| RoHS & halogen-free | Complies with IEC 61249-2-21 and EU RoHS Directive 2011/65/EU for green manufacturing |
| J-STD-020 MSL Level 1 | Unlimited floor life at ≤30 °C/60% RH - no bake required prior to reflow |
Applications
| Automotive Lighting Control | Industrial Sensor I/O Protection |
|---|---|
Use Scenario: Protecting LED driver ICs and CAN/LIN transceivers from load-dump surges and ESD in headlight modules. IC Role / Device Role / Timing Role: Unidirectional TVS placed between battery rail and regulator input to clamp transients before LDO or buck controller. Use Value: Limits clamped voltage to 80.3 V during 7.8 A 10/1000 µs surge, preventing overvoltage failure of 48 V-rated power management ICs. | Use Scenario: Safeguarding analog front-end inputs (e.g., 4–20 mA loop receivers) in PLC analog modules exposed to field wiring transients. IC Role / Device Role / Timing Role: Placed across input terminals to shunt fast transients while maintaining low leakage (<1 µA) during normal operation. Use Value: Maintains signal integrity with <1 µA blocking leakage at 45 V, avoiding offset errors in precision current-sense amplifiers. |
| DC Power Rail Protection | ESD-Sensitive Communication Interface |
Use Scenario: Guarding 48 V DC input rails in telecom power supplies against coupling from adjacent switching stages. IC Role / Device Role / Timing Role: Mounted at board edge to absorb coupled energy before reaching primary-side controllers and gate drivers. Use Value: Delivers 600 W peak pulse power handling with 55 °C/W RθJA, enabling robust protection without thermal runaway under repeated surges. | Use Scenario: Protecting RS-485 transceiver data lines in building automation systems subject to cable-induced ESD and lightning-induced surges. IC Role / Device Role / Timing Role: Bidirectional protection not applicable; SMBJ45 used on power-supply pins (VCC/GND) of transceiver ICs. Use Value: Sub-1 ps response ensures clamping initiates before transceiver internal ESD structures fail, preserving bus reliability. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ45A | Narrower VBR range (50.0–55.3 V), lower clamping voltage (72.7 V @ 8.6 A), tighter tolerance | Better suited for systems requiring tighter voltage margin between VWM and VC, e.g., 48 V nominal rails with strict overvoltage limits | Select SMBJ45A when clamping voltage headroom is constrained and tighter VBR consistency improves system margin. |
| SMAJ45 | Lower PPK (400 W), higher RθJA (85 °C/W), same DO-214AC (SMA) footprint but smaller thermal mass | Not suitable for sustained or repetitive surge conditions where SMBJ45's 600 W rating and lower thermal resistance are required | Choose SMAJ45 only for space-constrained designs with lower surge severity and adequate board copper for heat spreading. |
Compared with SMBJ45, SMBJ45A offers improved clamping consistency at the cost of slightly reduced surge current capacity, while SMAJ45 trades peak power and thermal performance for smaller footprint-making SMBJ45 the optimal balance of robustness, thermal management, and PCB area in mid-to-high severity 48 V system protection.
Availability
SMBJ45 is available at Aetrix Electronics and suitable for automotive lighting control, industrial sensor I/O protection, and DC power rail protection requiring stable component supply, full traceability, and long-term lifecycle support.
Supply support for SMBJ45 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 semiconductor manufacturer specializing in discrete power devices, TVS diodes, rectifiers, and MOSFETs for industrial, automotive, and consumer applications.
The SMBJ series was developed to deliver high-reliability, AEC-Q101 qualified transient suppression in compact surface-mount packages for harsh-environment DC power and signal line protection.
FAQ
What is the maximum clamping voltage of SMBJ45 under standard 10/1000 µs surge conditions?
The SMBJ45 has a maximum clamping voltage (VC) of 80.3 V when subjected to a 7.8 A peak impulse current with a 10/1000 µs waveform. This value is measured per ANSI/IEEE C62.35 and defines the upper voltage limit imposed on protected circuitry during surge events. The SMBJ45 maintains this clamping performance across its specified operating temperature range and is validated per ISO 7637-2 test pulses.
Is SMBJ45 suitable for bidirectional transient protection?
No, SMBJ45 is a unidirectional TVS diode and is not rated for bidirectional operation. Its electrical specifications-including breakdown voltage, clamping behavior, and polarity marking-apply only in reverse-bias mode. For bidirectional protection, the SMBJ45C or SMBJ45CA variant must be selected, as explicitly stated in the datasheet's "Devices for Bipolar Applications" section.
What is the leakage current specification for SMBJ45 at its working stand-off voltage?
The SMBJ45 exhibits a maximum blocking leakage current (ID) of 1 µA when biased at its 45 V working stand-off voltage (VWM). This low leakage ensures minimal impact on power efficiency and signal accuracy in always-on or high-impedance circuits such as sensor bias networks or precision reference paths. The value is guaranteed at TA = 25°C and remains well below 5 µA across the full -55°C to +150°C junction temperature range.
Does SMBJ45 comply with automotive surge immunity standards?
Yes, SMBJ45 meets ISO 7637-2 requirements for Pulse 1 (inductive load dump), Pulse 2a/2b (battery disconnection), and Pulse 3a/3b (capacitive switching transients). This compliance is explicitly documented in the product features table and confirmed through standardized test waveforms. The device's 600 W peak power rating and 80.3 V clamping voltage make it suitable for protecting ECUs, lighting modules, and body control units in 12 V and 48 V vehicle architectures.
What is the thermal resistance from junction to ambient for SMBJ45, and how does it affect layout design?
The SMBJ45 has a junction-to-ambient thermal resistance (RθJA) of 55 °C/W under standard JEDEC test conditions. This value directly impacts PCB layout: adequate copper pour (≥1 cm² per pad), thermal vias under the cathode/anode pads, and proximity to airflow or heatsinking are recommended to maintain TJ ≤ 150 °C during repetitive surge events. Layouts omitting thermal relief may exceed junction limits under sustained 600 W pulse duty cycles.
SMBJ45 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Taiwan Semiconductor Corporation
- Package/Case:
- DO-214AA, SMB
- Series:
- SMBJ
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 45V
- Voltage - Breakdown (Min):
- 50V
- Voltage - Clamping (Max) @ Ipp:
- 80.3V
- Current - Peak Pulse (10/1000µs):
- 7.8A
- 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)
SMBJ45 FAQ
1.How can I place an order for SMBJ45 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMBJ45 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 SMBJ45 reliable?
The price and inventory of SMBJ45 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMBJ45 is usually 5 days.
3.What payment methods are accepted for SMBJ45?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMBJ45 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMBJ45?
SMBJ45 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMBJ45 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 SMBJ45?
For technical support, including SMBJ45 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMBJ45 requirements.
6.How does Aetrix verify that SMBJ45 is sourced from the original manufacturer or authorized distributors?
All SMBJ45 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 SMBJ45 meets industry standards.
7.What is the process for return or replacement of SMBJ45?
All SMBJ45 units undergo pre-shipment inspection (PSI). If there is an issue with SMBJ45, 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 SMBJ45 part is unused and in its original packaging.
Return procedure for SMBJ45:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMBJ45 Tags
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