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Taiwan Semiconductor Corporation SMBJ20
- Part No.:
- SMBJ20
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SMBJ20.pdf
- Description:
- 600W, 24.7V, 10%, UNIDIRECTIONAL
- Quantity:
- Payment:
- Shipping:
Inventory:5,153
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Product details
Overview
SMBJ20 from Taiwan Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode in DO-214AA (SMB) package, rated for 600W peak pulse power, 20V working stand-off voltage (VWM), and clamps transients to ≤35.8V at 17.6A peak current. It protects automotive and industrial power rails against ISO 7637-2 Pulse 1/2a/2b/3a/3b surges.
For engineers reviewing the SMBJ20 datasheet, SMBJ20 pinout, SMBJ20 application, or SMBJ20 equivalent, key selection criteria include its 22.2–27.1V breakdown voltage range, <1μA leakage at 20V, 1.0ps response time, and compliance with JESD201 Class 2 whisker resistance and UL 94V-0 molding compound.
Technical Context
The SMBJ20 operates as a unidirectional avalanche diode, triggering when reverse voltage exceeds its VBR (22.2–27.1V @ 1mA). Its glass-passivated junction ensures stable breakdown and low leakage (<1μA @ VWM = 20V), while its DO-214AA thermal design delivers RθJA = 55°C/W and RθJC = 10°C/W.
It meets ISO 7637-2 immunity requirements for automotive electronics and supports surge handling up to 100A IFSM (8.3ms half-sine) in unidirectional configuration. Polarity is marked by cathode band; no bidirectional operation unless specified with 'C' or 'CA' suffix.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 20 V - Maximum continuous reverse operating voltage before clamping begins |
| VBR min/max | 22.2 / 27.1 V @ 1 mA - Confirmed breakdown range defining turn-on threshold tolerance |
| VC @ IPP | 35.8 V @ 17.6 A - Clamping voltage during 10/1000µs surge, limiting downstream stress |
| PPK | 600 W - Peak pulse power rating per 10/1000µs waveform, derated above 25°C |
| ID @ VWM | <1 µA - Low leakage preserves signal integrity and minimizes standby power loss |
| TJ max | +150 °C - Maximum junction temperature enabling operation in under-hood automotive environments |
| Package | DO-214AA (SMB) - Standardized surface-mount outline with 0.090g mass and matte tin leads |
Pinout & Package
DO-214AA (SMB) package: molded epoxy case with cathode band marking polarity; matte tin-plated leads compliant with J-STD-002 solderability and JESD201 Class 2 whisker resistance; UL 94V-0 flammability rating.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal | Connected to system ground or lower-potential rail in unidirectional TVS configuration |
| Cathode | Reverse-biased clamping terminal | Connected to protected line (e.g., 24V supply); cathode band identifies this terminal physically |
Key Features
| Feature | Design Value |
|---|---|
| Glass-passivated junction | Ensures repeatable, stable breakdown voltage and long-term reliability under repeated surge stress |
| Fast response time <1.0 ps | Clamps ESD and EFT transients before sensitive ICs experience overvoltage damage |
| ISO 7637-2 compliance (Pulse 1/2a/2b/3a/3b) | Validated for automotive load-dump and inductive-switching immunity without external filtering |
| Moisture sensitivity level 1 | Enables standard SMT reflow without baking or special handling prior to assembly |
| Halogen-free & RoHS-compliant | Meets IEC 61249-2-21 and global environmental directives for industrial and automotive use |
Applications
| Automotive Power Rail Protection | Industrial PLC Input Protection |
|---|---|
Use Scenario: Protecting 24V battery-fed ECUs from load dump and alternator transients in passenger vehicles. IC Role / Device Role / Timing Role: Unidirectional TVS placed between power rail and chassis ground to clamp surges exceeding 20V. Use Value: Limits peak voltage to ≤35.8V during 10/1000µs pulses, preventing damage to MCU power supplies and CAN transceivers. | Use Scenario: Safeguarding digital input channels of programmable logic controllers exposed to field-wiring inductive kickback. IC Role / Device Role / Timing Role: Standoff protection on 24V DC inputs, absorbing energy from relay coil de-energization. Use Value: Withstands 100A IFSM (8.3ms) and clamps transients within 1.0ps, eliminating need for additional RC snubbers. |
| LED Driver Overvoltage Suppression | Medical Equipment EFT Immunity |
Use Scenario: Preventing catastrophic failure of constant-current LED drivers subjected to accidental 48V connection or lightning-induced surges. IC Role / Device Role / Timing Role: Primary overvoltage clamp on input stage, placed upstream of DC-DC controller ICs. Use Value: 600W PPK rating handles high-energy events; <1μA leakage avoids interference with precision current sensing. | Use Scenario: Enhancing immunity of patient-monitoring device power inputs to IEC 61000-4-4 Electrical Fast Transients (EFT). IC Role / Device Role / Timing Role: Front-end transient suppression on AC/DC adapter output rails feeding analog front-end circuitry. Use Value: Meets ISO 7637-2 Pulse 3a/3b requirements and provides sub-36V clamping to protect 3.3V/5V LDOs and ADC references. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ20A | Narrower VBR range (22.2–24.5V vs. 22.2–27.1V); tighter tolerance improves predictability in precision-clamp designs | Better suited for systems requiring consistent clamping onset across temperature and unit variance | Select SMBJ20A when VBR consistency matters more than maximum surge margin |
| SMBJ22 | Higher VWM (22V) and VBR (24.4–29.8V); higher clamping voltage (39.4V @ 15A) | Used where 20V rail has larger noise margin or where higher standoff reduces false triggering | Choose SMBJ22 if system nominal voltage is ≥22V or if legacy layout uses same footprint with higher VWM headroom |
Compared with SMBJ20, SMBJ20A offers tighter VBR control for improved clamping repeatability, while SMBJ22 provides higher standoff for noisier 24V rails-both share DO-214AA packaging but differ in voltage grading and surge response thresholds.
Availability
SMBJ20 is available at Aetrix Electronics and suitable for automotive power rail protection, industrial PLC input conditioning, and LED driver overvoltage suppression requiring stable component supply and full traceability.
Supply support for SMBJ20 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 Taiwanese manufacturer specializing in discrete semiconductors, including TVS diodes, rectifiers, and MOSFETs for automotive and industrial markets.
The SMBJ series was designed specifically for robust, surface-mount transient suppression in harsh environments-emphasizing ISO 7637-2 compliance, high PPK density, and J-STD-020 Level 1 moisture resistance.
FAQ
What is the breakdown voltage range for SMBJ20?
The SMBJ20 has a minimum breakdown voltage (VBR) of 22.2 V and a maximum of 27.1 V, measured at 1 mA test current per ANSI/IEEE C62.35. This range defines the voltage at which the device transitions from high-impedance blocking to low-impedance clamping during transient events. The SMBJ20's specified VBR ensures reliable activation above its 20 V working stand-off voltage while accommodating process variation.
Is SMBJ20 unidirectional or bidirectional?
SMBJ20 is a unidirectional TVS diode, indicated by the absence of 'C' or 'CA' suffix. It conducts only in reverse bias to clamp positive transients on the cathode side and must be installed with correct polarity-cathode toward the protected line. Bidirectional variants (e.g., SMBJ20C) are separate part numbers with symmetrical breakdown in both directions.
What is the maximum clamping voltage of SMBJ20 under surge conditions?
The SMBJ20 clamps to a maximum of 35.8 V when subjected to its rated peak impulse current of 17.6 A using the standardized 10/1000 µs waveform. This VC value is guaranteed across temperature and unit-to-unit variation, ensuring downstream components see no more than 35.8 V during worst-case surge events. The SMBJ20 achieves this with minimal voltage overshoot due to its <1.0 ps response time.
Does SMBJ20 meet automotive surge immunity standards?
Yes, SMBJ20 meets ISO 7637-2 requirements for Pulse 1 (inductive load disconnect), Pulse 2a (sudden load removal), Pulse 2b (supply interruption), and Pulses 3a/3b (switching noise), making it suitable for 12 V and 24 V automotive subsystems. Its glass-passivated junction and DO-214AA thermal performance support sustained operation in under-hood environments up to +150 °C junction temperature.
What packaging and reel quantity is offered for SMBJ20?
SMBJ20 is supplied in DO-214AA (SMB) package on tape-and-reel format, with 3,000 units per reel. The package features matte tin-plated leads compliant with J-STD-002 solderability, UL 94V-0 molding compound, and JESD201 Class 2 whisker resistance. The SMBJ20 marking code is 'LU', visible on the cathode-band end of the device body.
SMBJ20 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):
- 20V
- Voltage - Breakdown (Min):
- 22.2V
- Voltage - Clamping (Max) @ Ipp:
- 35.8V
- Current - Peak Pulse (10/1000µs):
- 17.6A
- 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)
SMBJ20 FAQ
1.How can I place an order for SMBJ20 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMBJ20 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 SMBJ20 reliable?
The price and inventory of SMBJ20 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMBJ20 is usually 5 days.
3.What payment methods are accepted for SMBJ20?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMBJ20 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMBJ20?
SMBJ20 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMBJ20 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 SMBJ20?
For technical support, including SMBJ20 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMBJ20 requirements.
6.How does Aetrix verify that SMBJ20 is sourced from the original manufacturer or authorized distributors?
All SMBJ20 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 SMBJ20 meets industry standards.
7.What is the process for return or replacement of SMBJ20?
All SMBJ20 units undergo pre-shipment inspection (PSI). If there is an issue with SMBJ20, 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 SMBJ20 part is unused and in its original packaging.
Return procedure for SMBJ20:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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