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Taiwan Semiconductor Corporation SMBJ22A
- Part No.:
- SMBJ22A
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SMBJ22A.pdf
- Description:
- TVS DIODE 22VWM 35.5VC DO214AA
- Quantity:
- Payment:
- Shipping:
Inventory:10,929
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Product details
Overview
SMBJ22A 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 22 V working stand-off voltage (VWM), 24.4–26.9 V breakdown voltage (VBR), 35.5 V maximum clamping voltage (VC) at 17.7 A peak pulse current, and 600 W peak pulse power rating with <1.0 ps response time - deployed in automotive body control modules, industrial PLC I/O protection, and PoE-powered Ethernet interfaces.
For engineers reviewing the SMBJ22A datasheet, SMBJ22A pinout, SMBJ22A application, or SMBJ22A equivalent, key selection criteria include clamping performance under 10/1000 µs transients, leakage current ≤1 µA at 22 V, DO-214AA (SMB) package compatibility with automated SMT assembly, and compliance with ISO 7637-2 Pulse 1/2a/2b/3a/3b for automotive load-dump immunity.
Technical Context
The SMBJ22A operates as a unidirectional avalanche diode, leveraging glass-passivated junction technology to achieve fast transient response (<1.0 ps) and stable breakdown behavior across -55°C to +150°C junction temperature range. Its single-die DO-214AA construction enables low thermal resistance (RθJA = 55°C/W) and robust surge handling without degradation under repeated 10/1000 µs pulses.
It meets ISO 7637-2 requirements for automotive electronics, with verified clamping at 35.5 V under 17.7 A peak impulse current and forward surge capability of 100 A (8.3 ms half-sine). The device exhibits <1 µA blocking leakage at rated VWM, supporting low-power system monitoring circuits without parasitic loading.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 22 V - Maximum continuous reverse operating voltage before clamping begins; defines safe DC rail margin for 24 V systems. |
| VBR @ IT=1 mA | 24.4–26.9 V - Verified avalanche onset range; ensures predictable turn-on during fast transients without premature conduction. |
| VC @ IPP=17.7 A | 35.5 V - Clamped voltage under 10/1000 µs surge; limits downstream IC stress to safe levels in 24 V bus protection. |
| PPK | 600 W - Peak pulse power rating per 10/1000 µs waveform; supports high-energy ESD and load-dump events per ISO 7637-2. |
| ID @ VWM | <1 µA - Ultra-low reverse leakage at 22 V; avoids battery drain or sensor offset in always-on circuits. |
| TJ max | +150 °C - Maximum junction temperature; enables operation in under-hood automotive or enclosed industrial enclosures. |
| Package | DO-214AA (SMB) - Standardized surface-mount outline with 0.090 g mass; compatible with J-STD-002 soldering and JESD201 Class 2 whisker resistance. |
Pinout & Package
DO-214AA (SMB) package: molded plastic case with matte tin-plated leads, cathode band marking polarity, UL 94V-0 flammability rating, and J-STD-020 moisture sensitivity level 1.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward current path / Surge return path | Connected to ground or low-impedance return plane; carries full surge current during clamping. |
| Cathode | Protected line connection / High-side terminal | Connected to the line being protected (e.g., 24 V rail); blocks reverse leakage until VBR exceeded. |
Key Features
| Feature | Design Value |
|---|---|
| Glass-passivated junction | Ensures stable VBR tolerance and long-term reliability under thermal cycling and humidity exposure. |
| Clamping voltage ≤35.5 V at 17.7 A | Guarantees downstream 3.3 V/5 V logic ICs remain within absolute maximum ratings during ISO 7637-2 Pulse 2b events. |
| Response time <1.0 ps | Engages before transient energy couples into sensitive analog or digital circuitry, preventing latch-up or damage. |
| RoHS & halogen-free compliance | Meets IEC 61249-2-21 and EU RoHS directives for environmentally constrained industrial and automotive supply chains. |
| ISO 7637-2 certified | Validated for Pulse 1 (inductive switch-off), Pulse 2a/2b (battery disconnect/load dump), and Pulse 3a/3b (line transients). |
Applications
| Automotive Body Control Module (BCM) | Industrial PLC Digital Input Protection |
|---|---|
Use Scenario: Protecting microcontroller GPIOs and CAN transceiver power rails from load-dump surges during battery disconnection. IC Role / Device Role: Unidirectional TVS placed between 24 V supply and ground, clamping transients before they reach LDOs or interface ICs. Use Value: Limits clamped voltage to 35.5 V, keeping downstream 40 V-rated input stages within safe operating area during 100 V/50 ms load-dump events. |
Use Scenario: Shielding 24 V dry-contact digital inputs from inductive kickback when solenoids or relays de-energize. IC Role / Device Role: Standoff protection on field-side input traces, absorbing >600 W surge energy without failure. Use Value: Withstands 100 A forward surge (8.3 ms) and maintains <1 µA leakage, preserving input threshold accuracy in low-current sensing circuits. |
| PoE-Powered Ethernet Switch Port | LED Driver Power Supply Rail |
Use Scenario: Safeguarding PHY and PMIC components on IEEE 802.3af/at powered device (PD) ports against cable-induced surges. IC Role / Device Role: Primary DC rail clamp on the PD's 48 V input, coordinated with upstream current limiting. Use Value: Delivers 35.5 V clamping at 17.7 A, ensuring 50 V-rated DC-DC controllers survive 10/1000 µs transients up to 600 W. |
Use Scenario: Preventing overvoltage damage to constant-current LED driver ICs during hot-plug or capacitor discharge events. IC Role / Device Role: Parallel-connected TVS on the driver's VIN pin, shunting surge current away from internal FETs and references. Use Value: Maintains <1 µA leakage at 22 V, avoiding false triggering or regulation drift in precision current-sense feedback paths. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ22CA | Bidirectional variant; symmetric VBR (24.4–26.9 V) in both directions; same VC (35.5 V) and PPK (600 W). | Required for AC-coupled or dual-polarity signal lines (e.g., RS-485, CAN bus); not suitable for DC rail protection where polarity is fixed. | Select SMBJ22CA only when protecting bidirectional signals; SMBJ22A remains optimal for unidirectional 24 V power rails. |
| SMAJ22A | Lower PPK = 400 W; identical VWM (22 V), VBR (24.4–26.9 V), and VC (35.5 V); SMA package (smaller footprint, higher RθJA = 65°C/W). | Suitable for space-constrained consumer electronics with lower surge threat profiles; insufficient for ISO 7637-2 Pulse 2b compliance. | Choose SMAJ22A only for cost-sensitive, non-automotive designs with verified <400 W surge exposure; SMBJ22A is mandatory for automotive-grade immunity. |
Compared with SMBJ22CA and SMAJ22A, the SMBJ22A uniquely balances 600 W surge capacity, DO-214AA mechanical robustness, and unidirectional optimization for 24 V DC systems - making it the default choice for automotive and industrial power rail protection where peak energy and thermal margin are critical.
Availability
SMBJ22A is available at Aetrix Electronics and suitable for automotive body control modules, industrial PLC I/O protection, and PoE-powered Ethernet interfaces requiring stable component supply, full traceability, and long-term lifecycle support.
Supply support for SMBJ22A 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 was developed specifically for high-reliability transient suppression in harsh environments - emphasizing ISO 7637-2 compliance, low leakage, and robust DO-214AA packaging for automated SMT deployment in mission-critical systems.
FAQ
What is the maximum clamping voltage of SMBJ22A under standard test conditions?
The SMBJ22A has a maximum clamping voltage (VC) of 35.5 V when subjected to a 10/1000 µs surge current pulse of 17.7 A. This value is measured per ANSI/IEEE C62.35 and guarantees that downstream circuitry remains within safe voltage limits during standardized transient events - a critical parameter for protecting 3.3 V or 5 V logic interfaces fed from a 24 V rail.
Is SMBJ22A suitable for automotive applications requiring ISO 7637-2 compliance?
Yes, the SMBJ22A is explicitly tested and rated to meet ISO 7637-2 for Pulse 1 (inductive switch-off), Pulse 2a/2b (load dump), and Pulse 3a/3b (line transients). Its 600 W peak pulse power rating, 35.5 V clamping, and -55°C to +150°C operating range make it qualified for under-hood and chassis-mounted automotive ECUs - including body control modules and gateway units.
What is the difference between SMBJ22A and SMBJ22CA?
The SMBJ22A is unidirectional, with cathode-anode polarity and clamping only in reverse bias; the SMBJ22CA is bidirectional, offering symmetric clamping in both directions. Both share identical VWM (22 V), VBR (24.4–26.9 V), VC (35.5 V), and PPK (600 W), but SMBJ22CA is required for AC signals like CAN or RS-485, while SMBJ22A is optimized for DC power rail protection.
Does SMBJ22A have a specified junction capacitance value?
No junction capacitance (CJ) is specified for SMBJ22A in the official Taiwan Semiconductor datasheet (Version R2104). While Fig.5 shows typical CJ curves for the SMBJ family, no discrete value is published for SMBJ22A - indicating it is not characterized or guaranteed for high-frequency signal-line applications such as USB or HDMI protection.
What is the marking code for SMBJ22A and how is polarity indicated?
The marking code for SMBJ22A is "LX", laser-etched on the device body. Polarity is indicated by a cathode band - a visible stripe near one end of the DO-214AA (SMB) package - which identifies the cathode terminal. This band must be aligned toward the protected line (e.g., 24 V rail), while the anode connects to ground or return path.
SMBJ22A 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):
- 22V
- Voltage - Breakdown (Min):
- 24.4V
- Voltage - Clamping (Max) @ Ipp:
- 35.5V
- Current - Peak Pulse (10/1000µs):
- 16.9A
- Power - Peak Pulse:
- 600W
- Power Line Protection:
- Yes
- Applications:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AA (SMBJ)
SMBJ22A FAQ
1.How can I place an order for SMBJ22A through Aetrix?
Please submit a Request for Quotation (RFQ) for SMBJ22A 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 SMBJ22A reliable?
The price and inventory of SMBJ22A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMBJ22A is usually 5 days.
3.What payment methods are accepted for SMBJ22A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMBJ22A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMBJ22A?
SMBJ22A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMBJ22A 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 SMBJ22A?
For technical support, including SMBJ22A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMBJ22A requirements.
6.How does Aetrix verify that SMBJ22A is sourced from the original manufacturer or authorized distributors?
All SMBJ22A 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 SMBJ22A meets industry standards.
7.What is the process for return or replacement of SMBJ22A?
All SMBJ22A units undergo pre-shipment inspection (PSI). If there is an issue with SMBJ22A, 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 SMBJ22A part is unused and in its original packaging.
Return procedure for SMBJ22A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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