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Taiwan Semiconductor Corporation SMAJ11
- Part No.:
- SMAJ11
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ11.pdf
- Description:
- 400W, 13.6V, 10%, UNIDIRECTIONAL
- Quantity:
- Payment:
- Shipping:
Inventory:6,727
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Product details
Overview
SMAJ11 from Taiwan Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode in DO-214AC (SMA) package, designed for clamping fast transients on DC power lines and signal paths. It features a 11 V working stand-off voltage (VWM), 12.2–14.9 V breakdown voltage (VBR), 20.1 V maximum clamping voltage (VC) at 19.9 A peak pulse current, and 400 W peak pulse power rating with 10/1000 µs waveform.
For engineers reviewing the SMAJ11 datasheet, SMAJ11 pinout, SMAJ11 application, or SMAJ11 equivalent, key selection criteria include clamping performance under ISO 7637-2 Pulse 1/2a/2b/3a/3b, low leakage (<1 µA at VWM), fast response (<1.0 ps), and compatibility with automated SMT placement in SMPS, DC/DC converters, and lighting systems.
Technical Context
The SMAJ11 operates as a unidirectional avalanche diode, conducting only when reverse voltage exceeds its breakdown threshold. Its glass-passivated junction ensures stable VBR tolerance and low leakage, while the DO-214AC package provides robust thermal dissipation for 1 W steady-state power handling and 400 W transient surge absorption.
It meets automotive-grade transient immunity per ISO 7637-2 across all five pulse types and complies with J-STD-020 moisture sensitivity level 1. The device is rated for operation from –55 °C to +150 °C junction temperature, supporting deployment in harsh industrial and automotive environments without derating below 25 °C ambient.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 11 V - Maximum continuous reverse operating voltage before clamping begins; defines safe DC bias margin. |
| VBR min/max | 12.2 V / 14.9 V - Breakdown occurs within this range at 1 mA test current; ensures predictable turn-on timing. |
| VC @ IPPM | 20.1 V at 19.9 A - Clamped voltage during 10/1000 µs surge; limits downstream IC stress to ≤20.1 V. |
| PPPM | 400 W - Peak pulse power handling capability; supports high-energy transients in automotive load-dump scenarios. |
| IR @ VWM | <1 µA - Ultra-low reverse leakage at working voltage; prevents parasitic loading in battery-powered circuits. |
| TJ max | +150 °C - Maximum junction temperature; enables use in enclosed, high-ambient-temperature applications. |
| Package | DO-214AC (SMA) - Standard surface-mount outline with cathode band marking; compatible with IPC-7351B footprint. |
Pinout & Package
DO-214AC (SMA) package: molded plastic case with matte tin-plated leads, polarity indicated by cathode band. Weight ≈ 0.060 g. Meets UL 94V-0 flammability and JESD201 Class 2 whisker resistance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal | Connected to lower-potential side (e.g., GND or return path); conducts during forward surge or ESD events. |
| Cathode | Reverse-biased clamping terminal | Connected to protected line (e.g., 12 V rail); avalanches into conduction when transient exceeds VBR, shunting energy to ground. |
Key Features
| Feature | Design Value |
|---|---|
| Glass-passivated junction | Ensures tight VBR tolerance (±5% typical), stable leakage, and long-term reliability under thermal cycling. |
| Clamping voltage ≤20.1 V at 19.9 A | Protects 12 V logic and power rails by limiting transient overvoltage to safe levels below IC absolute maximum ratings. |
| Response time <1.0 ps | Engages before most microsecond-scale transients fully develop-critical for protecting high-speed interfaces and MCU I/O. |
| ISO 7637-2 compliance (Pulse 1/2a/2b/3a/3b) | Validated for automotive electronics immunity; eliminates need for additional external filtering in 12 V vehicle subsystems. |
| Moisture sensitivity level 1 | Enables standard SMT reflow without baking; reduces manufacturing overhead and avoids moisture-induced popcorning. |
Applications
| Automotive Infotainment Power Rail | Industrial SMPS Input Stage |
|---|---|
Use Scenario: Protecting USB-C PD controller and display interface power inputs in head units exposed to load dump and jump-start transients. IC Role / Device Role / Timing Role: Unidirectional TVS placed between 12 V supply and local decoupling capacitor, clamping surges before they reach PMIC input. Use Value: Limits clamped voltage to 20.1 V, staying well below 28 V absolute max rating of common USB PD controllers and preventing latch-up or damage. | Use Scenario: Safeguarding primary-side controller ICs and MOSFET gate drivers in offline AC/DC adapters subjected to lightning-induced surges. IC Role / Device Role / Timing Role: Mounted across bulk capacitor terminals to absorb repetitive line transients and reduce stress on electrolytic capacitors and switching FETs. Use Value: 400 W peak power rating sustains multiple 10/1000 µs surges without degradation, extending adapter lifetime in industrial settings. |
| LED Driver Board Protection | On-Board DC/DC Converter Input |
Use Scenario: Shielding constant-current LED driver ICs from inductive kickback and hot-swap transients in architectural lighting systems. IC Role / Device Role / Timing Role: Placed at DC input connector to clamp fast-rising spikes generated by relay switching or cable disconnection. Use Value: Sub-µA leakage at 11 V VWM avoids unnecessary standby current draw, preserving energy efficiency in always-on lighting controls. | Use Scenario: Securing 5 V or 3.3 V point-of-load (POL) converter inputs in embedded computing modules powered from shared 12 V backplanes. IC Role / Device Role / Timing Role: Installed upstream of buck converter input filter to prevent transient coupling into control loop and output regulation instability. Use Value: Fast <1 ps response ensures clamping initiates before feedback loop reacts, avoiding brownouts or reset events during bus transients. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ11A | Narrower VBR range (12.2–13.5 V vs. 12.2–14.9 V); lower VC = 18.2 V at 22.0 A. | Better clamping margin for 12 V systems with tight voltage tolerances; slightly reduced surge current capacity. | Select SMAJ11A when system-level testing shows 18.2 V clamping improves margin over downstream 13.2 V-rated components. |
| SMBJ11 | Same VWM/VBR/VC specs but in larger DO-214AA (SMB) package; higher thermal mass and 600 W PPPM rating. | Preferred where board space allows and higher surge endurance is required (e.g., front-end protection in EV charging modules). | Choose SMBJ11 if layout permits larger footprint and long-term reliability under repeated high-energy transients is prioritized. |
Compared with SMAJ11, SMAJ11A offers tighter clamping voltage at the cost of reduced VBR spread, while SMBJ11 trades smaller size for greater thermal robustness and surge handling-enabling design flexibility across cost, space, and ruggedness requirements.
Availability
SMAJ11 is available at Aetrix Electronics and suitable for automotive infotainment systems, industrial switch-mode power supplies, and LED lighting applications requiring stable component supply, RoHS-compliant packaging, and ISO 7637-2 validated transient immunity.
Supply support for SMAJ11 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 analog and discrete semiconductor manufacturer headquartered in Hsinchu, Taiwan, specializing in TVS diodes, rectifiers, MOSFETs, and power management devices.
The SMAJ series was developed specifically for surface-mount transient suppression in automotive and industrial power systems, emphasizing high surge robustness, tight parametric consistency, and automated assembly compatibility.
FAQ
What is the maximum clamping voltage of the SMAJ11 under a 10/1000 µs surge?
The SMAJ11 has a maximum clamping voltage (VC) of 20.1 V when subjected to its rated peak pulse current of 19.9 A using the standardized 10/1000 µs waveform. This value is measured per JEDEC standards and guarantees that protected circuitry will not experience voltages exceeding 20.1 V during such transient events. The SMAJ11 maintains this clamping performance across its full operating temperature range.
Is the SMAJ11 suitable for bidirectional transient protection?
No, the SMAJ11 is a unidirectional TVS diode intended for DC line protection where polarity is fixed. For bidirectional applications-such as AC signal lines or data buses-Taiwan Semiconductor specifies the SMAJ11CA variant (with "CA" suffix), which provides symmetrical clamping in both directions. Using SMAJ11 in reverse-biased configurations beyond its specified VWM may result in unintended conduction or failure.
Does the SMAJ11 meet automotive qualification standards?
Yes, the SMAJ11 meets ISO 7637-2 Pulse 1, 2a, 2b, 3a, and 3b requirements for electrical disturbances in road vehicles, making it suitable for 12 V automotive subsystems including body control modules and infotainment power supplies. While it is not AEC-Q200 qualified as a standalone component, its electrical behavior and construction align with automotive transient immunity test profiles.
What is the leakage current specification for the SMAJ11 at its working voltage?
The SMAJ11 exhibits a maximum reverse leakage current (IR) of 1 µA when biased at its working stand-off voltage (VWM) of 11 V and tested at 25 °C. This ultra-low leakage ensures minimal power loss in battery-backed or energy-sensitive applications and avoids false triggering in high-impedance sensing circuits. Leakage remains below 1 µA across the full –55 °C to +125 °C operating range.
Can the SMAJ11 be used in place of the SMAJ11A?
The SMAJ11 and SMAJ11A are not direct drop-in replacements due to differences in breakdown voltage spread and clamping performance: SMAJ11 has VBR = 12.2–14.9 V and VC = 20.1 V, whereas SMAJ11A has VBR = 12.2–13.5 V and VC = 18.2 V. Substituting SMAJ11 for SMAJ11A may raise clamping voltage beyond system margins; verification against downstream component ratings and transient test results is required before interchange.
SMAJ11 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Taiwan Semiconductor Corporation
- Package/Case:
- DO-214AC, SMA
- Series:
- SMAJ
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 11V
- Voltage - Breakdown (Min):
- 12.2V
- Voltage - Clamping (Max) @ Ipp:
- 20.1V
- Current - Peak Pulse (10/1000µs):
- 19.9A
- Power - Peak Pulse:
- 400W
- 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-214AC (SMA)
SMAJ11 FAQ
1.How can I place an order for SMAJ11 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ11 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 SMAJ11 reliable?
The price and inventory of SMAJ11 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ11 is usually 5 days.
3.What payment methods are accepted for SMAJ11?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ11 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ11?
SMAJ11 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ11 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 SMAJ11?
For technical support, including SMAJ11 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ11 requirements.
6.How does Aetrix verify that SMAJ11 is sourced from the original manufacturer or authorized distributors?
All SMAJ11 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 SMAJ11 meets industry standards.
7.What is the process for return or replacement of SMAJ11?
All SMAJ11 units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ11, 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 SMAJ11 part is unused and in its original packaging.
Return procedure for SMAJ11:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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