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Taiwan Semiconductor Corporation SMBJ51
- Part No.:
- SMBJ51
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SMBJ51.pdf
- Description:
- 600W, 63V, 10%, UNIDIRECTIONAL,
- Quantity:
- Payment:
- Shipping:
Inventory:6,689
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Product details
Overview
SMBJ51 from Taiwan Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode designed for high-energy ESD and surge protection in DC power rails and signal lines. It features a 51 V working stand-off voltage (VWM), 56.7–69.3 V breakdown voltage (VBR) at 1 mA, 91.1 V maximum clamping voltage (VC) at 6.9 A peak pulse current, and 600 W peak pulse power rating with 10/1000 µs waveform - deployed in automotive infotainment power inputs and industrial PLC I/O modules.
For engineers reviewing the SMBJ51 datasheet, SMBJ51 pinout, SMBJ51 application, or SMBJ51 equivalent, key selection criteria include clamping performance under ISO 7637-2 Pulse 1/2a/2b/3a/3b, junction-to-ambient thermal resistance (55 °C/W), moisture sensitivity level (MSL 1), and DO-214AA (SMB) package compatibility with automated SMT assembly.
Technical Context
The SMBJ51 operates as a unidirectional avalanche diode, triggering when reverse voltage exceeds its VBR range (56.7–69.3 V) to shunt transients away from protected circuitry. Its glass-passivated junction ensures stable leakage (<1 µA at 51 V) and fast response (<1.0 ps), critical for suppressing EFT bursts and load-dump spikes.
Thermally, it sustains 150 °C maximum junction temperature with 10 °C/W junction-to-case and 55 °C/W junction-to-ambient resistance. Its DO-214AA (SMB) package supports 3 W steady-state dissipation and 100 A non-repetitive forward surge (8.3 ms half-sine), enabling robust protection in 12 V/24 V automotive and industrial systems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 51 V - Maximum continuous reverse operating voltage before clamping begins; defines safe DC rail margin for 48 V nominal systems. |
| VBR @ IT=1 mA | 56.7–69.3 V - Breakdown threshold range; ensures reliable turn-on during transients while avoiding false triggering on ripple or noise. |
| VC @ IPP=6.9 A | 91.1 V - Clamped voltage under 10/1000 µs surge; limits downstream IC stress to <92 V during 600 W transient events. |
| PPK | 600 W - Peak pulse power handling per 10/1000 µs waveform; meets ISO 7637-2 Pulse 1 (inductive switch-off) and Pulse 2b (battery dump) requirements. |
| ID @ VWM | <1 µA - Reverse leakage at 51 V; minimizes standby power loss and avoids false resets in low-power sensor nodes. |
| TJ max | +150 °C - Maximum junction temperature; enables operation in under-hood automotive environments and enclosed industrial enclosures. |
| RθJA | 55 °C/W - Thermal resistance from junction to ambient; informs PCB copper area requirements for sustained 3 W power dissipation. |
Pinout & Package
Package: DO-214AA (SMB), surface-mount, single-diode configuration with cathode band marking. Matte tin-plated leads meet J-STD-002 solderability; MSL Level 1 per J-STD-020.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal | Connected to ground or lower-potential node; completes current path during clamping of positive transients on cathode side. |
| Cathode | Reverse-biased clamping terminal | Connected to protected line (e.g., 48 V supply rail); avalanches into conduction when voltage exceeds VBR, diverting surge to ground. |
Key Features
| Feature | Design Value |
|---|---|
| Glass-passivated junction | Ensures stable VBR tolerance and long-term reliability under thermal cycling and humidity exposure in automotive-grade applications. |
| Clamping time <1.0 ps | Responds faster than most microcontrollers and communication ICs can be damaged, providing effective protection against ESD and EFT events. |
| ISO 7637-2 compliance | Validated for Pulse 1 (inductive load disconnect), Pulse 2a (supply line transient), Pulse 2b (battery feed interruption), and Pulses 3a/3b (switching noise). |
| RoHS & halogen-free | Meets IEC 61249-2-21 and EU RoHS Directive; suitable for environmentally regulated industrial and consumer electronics manufacturing. |
| Automated placement compatible | DO-214AA (SMB) footprint and matte tin plating support high-yield pick-and-place and reflow soldering per IPC-J-STD-001. |
Applications
| Automotive Power Input Protection | Industrial Sensor Signal Line Protection |
|---|---|
Use Scenario: Protecting infotainment head-unit 12 V/24 V power input against load-dump surges and alternator ripple. IC Role / Device Role / Timing Role: Unidirectional TVS clamping device placed between power rail and ground, activated within picoseconds of overvoltage onset. Use Value: Limits clamped voltage to 91.1 V during 600 W transients, preventing damage to upstream DC-DC controllers and downstream SoCs rated for ≤100 V absolute maximum. |
Use Scenario: Shielding 4–20 mA analog sensor outputs from ESD and switching noise in factory automation I/O modules. IC Role / Device Role / Timing Role: Low-leakage (≤1 µA) TVS connected across signal and return lines to absorb ±8 kV contact ESD per IEC 61000-4-2 without affecting loop accuracy. Use Value: Maintains signal integrity with <1 µA leakage at 51 V stand-off, ensuring full-scale error remains below 0.005% in precision current loops. |
| LED Driver Overvoltage Clamp | PLC Digital Input Protection |
Use Scenario: Safeguarding constant-current LED driver ICs from inductive kickback during MOSFET switching in streetlight ballasts. IC Role / Device Role / Timing Role: Fast-response TVS placed across driver output to clamp flyback spikes before they exceed the IC's 60 V absolute maximum rating. Use Value: Clamps 10/1000 µs surges to ≤91.1 V at 6.9 A, keeping driver junction temperature rise within safe limits during repetitive switching cycles. |
Use Scenario: Protecting 24 V digital input channels in programmable logic controllers from field-wiring transients and relay coil back-EMF. IC Role / Device Role / Timing Role: Standoff-rated TVS (51 V) installed at connector entry point to shunt >1 kV transients before reaching optocoupler input stages. Use Value: Withstands 600 W pulses per ISO 7637-2 Pulse 1, enabling reliable operation in harsh factory floor environments with minimal external filtering. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ51A | Narrower VBR range (56.7–62.7 V vs. 56.7–69.3 V); tighter 5% tolerance; same VWM (51 V), VC (82.4 V @ 7.6 A), and PPK (600 W). | Better suited for designs requiring precise clamping threshold control and lower VC under identical IPP, especially in safety-critical 48 V telecom power supplies. | Select SMBJ51A when tighter VBR distribution and lower clamping voltage are prioritized over cost; verify layout accommodates identical DO-214AA footprint. |
| SAC51 | Same VWM (51 V) and DO-214AA package, but lower PPK (400 W); higher VC (95 V @ 4.2 A); not ISO 7637-2 certified. | Limited to less demanding consumer-grade applications where full automotive surge immunity is not required. | Choose SAC51 only for cost-sensitive, non-automotive designs with lower surge energy expectations; avoid in ISO-compliant systems. |
Compared with SMBJ51, SMBJ51A offers tighter VBR control and lower clamping voltage for enhanced precision protection, while SAC51 sacrifices surge rating and certification for cost reduction - making SMBJ51 the balanced choice for industrial and automotive applications requiring verified 600 W immunity.
Availability
SMBJ51 is available at Aetrix Electronics and suitable for automotive power inputs, industrial sensor interfaces, LED driver circuits, and PLC digital inputs requiring stable component supply with full ISO 7637-2 compliance and MSL Level 1 handling.
Supply support for SMBJ51 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 automotive, industrial, and computing markets.
The SMBJ series is part of TSC's high-reliability transient suppression portfolio, engineered specifically for robust surge immunity in 12 V/24 V/48 V systems subject to ISO 7637-2 and IEC 61000-4-5 stress conditions.
FAQ
What is the clamping voltage of SMBJ51 under standard test conditions?
The SMBJ51 has a maximum clamping voltage (VC) of 91.1 V when subjected to a 10/1000 µs surge waveform at 6.9 A peak pulse current (IPP). This value is measured per ANSI/IEEE C62.35 and reflects worst-case clamping performance under standardized transient conditions - critical for verifying downstream IC voltage stress margins in 48 V system designs using SMBJ51.
Is SMBJ51 suitable for bidirectional transient protection?
No, SMBJ51 is a unidirectional TVS diode intended for DC rail protection where polarity is fixed. For bidirectional applications (e.g., AC signal lines or data buses), TSC specifies SMBJ51C or SMBJ51CA variants with symmetrical breakdown in both directions. Using SMBJ51 in reverse-biased AC configurations risks permanent failure due to forward conduction beyond its 3.5 V VF rating.
What is the maximum steady-state power dissipation for SMBJ51?
The SMBJ51 has a steady-state power dissipation (PD) rating of 3 W at TA = 25°C, derated linearly above that ambient temperature per the pulse derating curve in Figure 2 of the datasheet. This rating governs continuous power handling during prolonged overvoltage events or elevated ambient conditions - distinct from its 600 W non-repetitive peak pulse capability.
Does SMBJ51 comply with automotive surge immunity standards?
Yes, SMBJ51 meets ISO 7637-2 requirements for Pulses 1, 2a, 2b, 3a, and 3b - covering key automotive transients including load dump, battery disconnection, and inductive switching noise. Its 600 W peak pulse rating, 91.1 V clamping, and 150 °C junction rating make SMBJ51 suitable for front-end protection in automotive ECUs, body control modules, and infotainment systems.
What packaging and moisture sensitivity level does SMBJ51 have?
SMBJ51 is supplied in DO-214AA (SMB) package format on 3,000-piece tape-and-reel, with Moisture Sensitivity Level (MSL) 1 per J-STD-020 - meaning it may be stored indefinitely at ≤30 °C/60% RH without baking prior to reflow. Its matte tin-plated leads ensure compatibility with standard SnPb and lead-free soldering processes per J-STD-002.
SMBJ51 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):
- 51V
- Voltage - Breakdown (Min):
- 56.7V
- Voltage - Clamping (Max) @ Ipp:
- 91.1V
- Current - Peak Pulse (10/1000µs):
- 6.9A
- 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)
SMBJ51 FAQ
1.How can I place an order for SMBJ51 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMBJ51 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 SMBJ51 reliable?
The price and inventory of SMBJ51 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMBJ51 is usually 5 days.
3.What payment methods are accepted for SMBJ51?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMBJ51 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMBJ51?
SMBJ51 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMBJ51 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 SMBJ51?
For technical support, including SMBJ51 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMBJ51 requirements.
6.How does Aetrix verify that SMBJ51 is sourced from the original manufacturer or authorized distributors?
All SMBJ51 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 SMBJ51 meets industry standards.
7.What is the process for return or replacement of SMBJ51?
All SMBJ51 units undergo pre-shipment inspection (PSI). If there is an issue with SMBJ51, 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 SMBJ51 part is unused and in its original packaging.
Return procedure for SMBJ51:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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