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Taiwan Semiconductor Corporation SMAJ14H
- Part No.:
- SMAJ14H
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ14H.pdf
- Description:
- TVS DIODE 14VWM 25.8VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:8,994
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Product details
Overview
SMAJ14H from Taiwan Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode in DO-214AC (SMA) package, designed for robust overvoltage protection in DC power rails. It features a 14 V working stand-off voltage (VWM), 15.6–19.1 V breakdown voltage (VBR), 25.8 V maximum clamping voltage (VC) at 15.5 A peak pulse current, and 400 W peak pulse power rating per 10/1000 µs waveform - ideal for protecting automotive-grade DC/DC converters against ISO 7637-2 pulses.
For engineers reviewing the SMAJ14H datasheet, SMAJ14H pinout, SMAJ14H application, or SMAJ14H equivalent, key selection criteria include clamping performance under 15.5 A surge, unidirectional polarity marking, AEC-Q101 qualification, moisture sensitivity level 1 compliance, and compatibility with automated SMT placement on high-reliability power supply boards.
Technical Context
The SMAJ14H operates as a unidirectional avalanche diode, leveraging glass-passivated junction technology to achieve sub-1 ps response time and low leakage (<1 µA at 14 V). Its clamping behavior is defined by a tightly controlled VBR range (15.6–19.1 V @ 1 mA) and specified VC = 25.8 V @ IPPM = 15.5 A, ensuring predictable voltage limiting during transients such as load dump or inductive switching events.
It is rated for continuous operation from −55 °C to +150 °C junction temperature, supports 40 A non-repetitive forward surge (8.3 ms half-sine), and meets ISO 7637-2 Pulse 1, 2a, 2b, 3a, and 3b immunity requirements - confirming suitability for automotive power electronics where transient robustness and thermal stability are critical.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 14 V - Maximum continuous reverse operating voltage before conduction begins; sets system rail protection threshold. |
| VBR min/max | 15.6 / 19.1 V @ 1 mA - Breakdown onset range defining turn-on consistency across production lots. |
| VC @ IPPM | 25.8 V @ 15.5 A - Clamped voltage during 10/1000 µs surge; determines maximum stress on downstream ICs. |
| PPPM | 400 W - Peak pulse power handling capability; enables protection against high-energy transients without failure. |
| IR @ VWM | <1 µA - Ultra-low reverse leakage ensures minimal standby power loss in battery-critical systems. |
| TJ max | +150 °C - Maximum junction temperature rating supporting under-hood automotive deployment. |
| Package | DO-214AC (SMA) - Industry-standard surface-mount outline with cathode band marking and RoHS/halogen-free construction. |
Pinout & Package
DO-214AC (SMA) package: molded plastic case with matte tin-plated leads, polarity indicated by cathode band, weight ≈ 0.060 g, UL 94V-0 rated compound, JESD201 Class 2 whisker resistance, and moisture sensitivity level 1 (MSL-1).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Low-side reference terminal | Connected to ground or low-impedance return path; forms current sink during transient clamp. |
| Cathode | High-side input terminal | Connected to protected line (e.g., 12 V rail); marked by band; conducts avalanche current toward anode when VAK exceeds VBR. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive applications including temperature cycling, mechanical shock, and humidity testing per stress test plan. |
| Glass passivated junction | Enhances long-term reliability and stability of VBR and leakage under thermal and humidity stress. |
| Fast response time <1 ps | Enables suppression of ESD and fast-rising transients before sensitive circuitry sustains damage. |
| ISO 7637-2 compliant | Guarantees immunity to standardized automotive electrical disturbances including load dump and coupled noise pulses. |
| MSL-1 rating | Allows unlimited floor life and reflow without baking, simplifying SMT manufacturing flow. |
Applications
| Automotive On-Board DC/DC Converter | Industrial Switching Mode Power Supply (SMPS) |
|---|---|
Use Scenario: Protecting 12 V input stage of buck converter in engine control unit (ECU) against load dump and alternator ripple. IC Role / Device Role / Timing Role: Unidirectional TVS placed between VIN and GND to clamp surges above 14 V before they reach controller IC and MOSFET gate drivers. Use Value: Limits transient voltage to ≤25.8 V at 15.5 A, preventing latch-up or oxide breakdown in 30 V-rated power management ICs. | Use Scenario: Safeguarding auxiliary 24 V DC rail in factory automation PLC power module from inductive kickback and lightning-induced surges. IC Role / Device Role / Timing Role: Standoff protector on primary-side DC bus, absorbing repetitive 400 W pulses without degradation over >100,000 cycles. Use Value: Maintains <1 µA leakage at 14 V, avoiding unnecessary quiescent current draw in always-on industrial control systems. |
| LED Driver Power Input Stage | Automotive Lighting Module |
Use Scenario: Shielding constant-current LED driver IC from voltage spikes generated by relay switching in headlamp assemblies. IC Role / Device Role / Timing Role: Fast-clamping TVS placed directly at driver IC VIN pin to suppress sub-microsecond transients before internal LDO or gate driver stages. Use Value: Sub-1 ps response ensures clamping initiates before 10 ns edge rates propagate into analog current regulation circuitry. | Use Scenario: Overvoltage protection for CAN-connected interior lighting node exposed to battery disconnect transients and ESD events. IC Role / Device Role / Timing Role: Primary protection device on 12 V supply line upstream of CAN transceiver and microcontroller power rails. Use Value: AEC-Q101 qualification and ISO 7637-2 Pulse 3b compliance ensure functional safety integrity in ASIL-B relevant lighting subsystems. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ14AH | Narrower VBR range (15.6–17.2 V vs. 15.6–19.1 V); tighter tolerance improves clamping predictability but reduces margin for VBR drift at high temperature. | Better suited for precision-clamp designs where worst-case VC must stay below 24 V; less margin for aging or thermal derating. | Select SMAJ14AH when design requires tighter VBR distribution and can accommodate reduced surge margin at elevated temperature. |
| SMBJ14H | Same VWM/VBR/VC specs but in larger DO-214AA (SMB) package; higher PPPM = 600 W (vs. 400 W) and IPPM = 23.3 A. | Used where board space allows larger footprint and higher surge energy absorption is required (e.g., front-end main power input). | Choose SMBJ14H for applications demanding >400 W pulse handling or where thermal mass improves long-pulse survivability. |
Compared with SMAJ14AH and SMBJ14H, the SMAJ14H offers optimal balance of compact DO-214AC footprint, AEC-Q101 qualification, and 400 W surge capability - making it preferred for space-constrained, automotive-qualified DC/DC converter inputs where consistent clamping and MSL-1 manufacturability are prioritized.
Availability
SMAJ14H is available at Aetrix Electronics and suitable for automotive on-board DC/DC converters, industrial switching mode power supplies, and LED driver power input stages requiring stable component supply with full traceability and lifecycle continuity.
Supply support for SMAJ14H 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 automotive-qualified components with global distribution and AEC-Q101 validation capabilities.
The SMAJ series is part of TSC's automotive-grade transient suppression portfolio, engineered specifically for ISO 7637-2 compliance and under-hood deployment in 12 V/24 V vehicle electrical systems.
FAQ
What is the clamping voltage of SMAJ14H at its rated peak pulse current?
The SMAJ14H has a maximum clamping voltage (VC) of 25.8 V when subjected to its rated peak pulse current (IPPM) of 15.5 A under the standard 10/1000 µs waveform. This value is guaranteed across the full operating temperature range and defines the upper voltage limit imposed on protected circuitry during transient events - critical for ensuring downstream ICs remain within absolute maximum ratings. The SMAJ14H achieves this while maintaining low leakage and fast response.
Is SMAJ14H suitable for automotive applications?
Yes, SMAJ14H is AEC-Q101 qualified and explicitly tested to meet ISO 7637-2 Pulse 1, 2a, 2b, 3a, and 3b standards - confirming its suitability for automotive power networks including engine control units, body control modules, and lighting systems. Its DO-214AC package, MSL-1 rating, and −55 °C to +150 °C operating range further validate its readiness for under-hood deployment. The SMAJ14H is designed for these environments from wafer through final test.
How does SMAJ14H differ from SMAJ14AH?
The SMAJ14H and SMAJ14AH share identical VWM (14 V) and package (DO-214AC), but differ in breakdown voltage tolerance: SMAJ14H specifies VBR = 15.6–19.1 V, while SMAJ14AH tightens this to 15.6–17.2 V. This narrower range yields more predictable clamping onset and lower worst-case VC, but reduces margin for VBR drift at high temperature. Both parts retain identical 400 W PPPM and AEC-Q101 qualification. Designers select SMAJ14H for broader surge margin; SMAJ14AH for tighter voltage control.
What is the maximum reverse leakage current for SMAJ14H at its working voltage?
The SMAJ14H exhibits a maximum reverse leakage current (IR) of 1 µA when biased at its working stand-off voltage (VWM) of 14 V and measured at 25 °C. This ultra-low leakage is maintained across its full operating temperature range and contributes to minimal standby power loss - especially valuable in always-on automotive modules and battery-powered industrial sensors. The SMAJ14H achieves this while retaining fast avalanche response and robust surge handling.
Does SMAJ14H have polarity marking, and how is it identified?
Yes, SMAJ14H is a unidirectional TVS diode with explicit polarity marking: a cathode band is printed on the body end of the DO-214AC (SMA) package. This band corresponds to the cathode terminal, which must be connected to the protected line (e.g., 12 V rail), while the anode connects to ground. Correct orientation is essential - reverse connection renders the device ineffective for overvoltage protection. The SMAJ14H's marking code "BH" is laser-etched adjacent to the band per TSC's standard marking diagram.
SMAJ14H 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):
- 14V
- Voltage - Breakdown (Min):
- 15.6V
- Voltage - Clamping (Max) @ Ipp:
- 25.8V
- Current - Peak Pulse (10/1000µs):
- 15.5A
- Power - Peak Pulse:
- 400W
- Power Line Protection:
- No
- Applications:
- -
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AC (SMA)
SMAJ14H FAQ
1.How can I place an order for SMAJ14H through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ14H 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 SMAJ14H reliable?
The price and inventory of SMAJ14H are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ14H is usually 5 days.
3.What payment methods are accepted for SMAJ14H?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ14H transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ14H?
SMAJ14H orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ14H 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 SMAJ14H?
For technical support, including SMAJ14H datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ14H requirements.
6.How does Aetrix verify that SMAJ14H is sourced from the original manufacturer or authorized distributors?
All SMAJ14H 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 SMAJ14H meets industry standards.
7.What is the process for return or replacement of SMAJ14H?
All SMAJ14H units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ14H, 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 SMAJ14H part is unused and in its original packaging.
Return procedure for SMAJ14H:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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