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Taiwan Semiconductor Corporation SMAJ43
- Part No.:
- SMAJ43
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ43.pdf
- Description:
- 400W, 53.1V, 10%, UNIDIRECTIONAL
- Quantity:
- Payment:
- Shipping:
Inventory:5,040
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Product details
Overview
SMAJ43 from Taiwan Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode designed for overvoltage protection in DC power lines and signal paths. It features a 43 V working stand-off voltage (VWM), 47.8–58.4 V breakdown voltage (VBR) at 1 mA test current, 76.7 V maximum clamping voltage (VC) at 5.2 A peak impulse current, and 400 W peak pulse power rating with 10/1000 µs waveform - suitable for automotive load-dump and ISO 7637-2 Pulse 1/2a/2b/3a/3b compliance.
For engineers reviewing the SMAJ43 datasheet, SMAJ43 pinout, SMAJ43 application, or SMAJ43 equivalent, key selection criteria include clamping performance under 10/1000 µs transients, reverse leakage (<1 µA at 43 V), junction temperature range (–55 °C to +150 °C), DO-214AC package compatibility, and unidirectional polarity marking for correct PCB orientation.
Technical Context
The SMAJ43 operates as a silicon avalanche diode with glass-passivated junction, enabling fast response time (<1.0 ps from 0 V to VBR min) and stable clamping under repetitive surge events. Its single-die DO-214AC construction supports automated placement and meets JESD201 Class 2 whisker resistance and J-STD-020 Level 1 moisture sensitivity requirements.
Designed for unidirectional protection only, the SMAJ43 exhibits a maximum forward voltage of 3.5 V at 25 A surge and steady-state power dissipation of 1 W. Thermal derating begins above 25 °C ambient per Fig.2, maintaining safe operation up to 150 °C junction temperature with proper PCB copper area.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 43 V - Maximum continuous reverse operating voltage before clamping initiates |
| VBR min/max | 47.8 V / 58.4 V at 1 mA - Ensures reliable avalanche conduction onset across process variation |
| VC @ IPPM | 76.7 V at 5.2 A - Limits downstream circuit voltage during 10/1000 µs surge, protecting 48 V systems |
| PPPM | 400 W (10/1000 µs) - Sustains high-energy transients without failure in automotive and industrial environments |
| IR @ VWM | <1 µA - Negligible standby leakage, critical for low-power battery-backed circuits |
| TJ max | +150 °C - Enables use in under-hood automotive modules and enclosed power supplies |
| Package | DO-214AC (SMA) - Industry-standard surface-mount outline with cathode band polarity marking |
Pinout & Package
DO-214AC (SMA) package: molded plastic case with matte tin-plated leads, UL 94V-0 flammability rating, and cathode band indicating terminal polarity. Weight ≈ 0.060 g.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction path | Connected to protected line's lower-potential side (e.g., GND or return path) |
| Cathode | Avalanche clamping node | Connected to protected line's higher-potential side (e.g., 48 V rail); marked by band on package |
Key Features
| Feature | Design Value |
|---|---|
| Glass-passivated junction | Ensures long-term reliability and stable VBR over temperature and lifetime |
| Fast response time <1.0 ps | Clamps ESD and lightning-induced surges before sensitive ICs experience overstress |
| ISO 7637-2 compliance (Pulse 1/2a/2b/3a/3b) | Validated for automotive 12 V/24 V system-level EMC immunity testing |
| RoHS and halogen-free | Meets IEC 61249-2-21 and global environmental compliance mandates |
Applications
| Automotive Body Control Module | Industrial 48 V DC/DC Converter |
|---|---|
Use Scenario: Protecting LIN bus transceivers and microcontroller I/O against load dump and jump-start transients in vehicle door modules. IC Role / Device Role / Timing Role: Unidirectional TVS clamp placed between LIN line and ground, triggered within picoseconds of overvoltage event. Use Value: Limits voltage to ≤76.7 V during 10/1000 µs pulses, preventing damage to 5 V tolerant transceivers while maintaining <1 µA leakage during normal operation. | Use Scenario: Safeguarding primary-side MOSFET gate drivers and feedback optocouplers in isolated 48 V input DC/DC converters. IC Role / Device Role / Timing Role: Standoff-rated TVS on 48 V input rail, absorbing repetitive switching noise and external surge coupling. Use Value: Withstands 400 W peak pulses and operates up to +150 °C junction temperature, ensuring robustness in thermally constrained power stages. |
| LED Streetlight Power Supply | Telecom Remote Radio Unit (RRU) |
Use Scenario: Clamping induced surges on constant-current LED driver inputs exposed to outdoor lightning coupling. IC Role / Device Role / Timing Role: Primary overvoltage protector on AC-DC rectified output or DC input stage, oriented anode-to-ground. Use Value: 43 V VWM matches nominal 48 V system level; 76.7 V VC ensures downstream electrolytic capacitors and controllers remain within rated voltage margin. | Use Scenario: Protecting 48 V DC power interface of outdoor RRU equipment subjected to telecom-grade surge standards (IEC 61000-4-5). IC Role / Device Role / Timing Role: Front-end TVS on power entry board, coordinated with upstream MOVs and downstream filtering. Use Value: DO-214AC footprint enables high-density layout; <1 µA IR avoids battery drain in backup-powered configurations. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ43A | Narrower VBR range (47.8–52.8 V vs. 47.8–58.4 V); tighter tolerance improves clamping consistency | Better suited for precision 48 V systems where worst-case VC must be minimized | Select SMAJ43A when clamping voltage margin is critical and tighter VBR distribution justifies cost premium |
| SMBJ43 | Same VWM/VBR/VC specs but in larger DO-214AA (SMB) package; 600 W PPPM rating | Higher power handling supports longer-duration surges; requires larger PCB footprint | Choose SMBJ43 when system-level surge tests exceed 400 W or thermal mass demands greater dissipation |
Compared with SMAJ43A and SMBJ43, the SMAJ43 offers optimal balance of compact DO-214AC footprint, 400 W surge capability, and broad VBR tolerance - ideal for space-constrained 48 V applications where moderate clamping variation is acceptable.
Availability
SMAJ43 is available at Aetrix Electronics and suitable for automotive body electronics, industrial 48 V DC/DC converters, LED lighting power supplies, and telecom remote radio units requiring stable component supply and full traceability.
Supply support for SMAJ43 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 industrial, automotive, and consumer markets.
The SMAJ series was developed specifically for surface-mount transient suppression in harsh-environment DC power rails, emphasizing high surge robustness, tight thermal design margins, and automated assembly compatibility.
FAQ
What is the maximum clamping voltage of the SMAJ43 under standard 10/1000 µs surge conditions?
The SMAJ43 has a maximum clamping voltage (VC) of 76.7 V when subjected to its rated peak impulse current of 5.2 A using the 10/1000 µs waveform. This value is measured at TA = 25 °C and defines the upper voltage limit imposed on protected circuitry during transient events. The SMAJ43 maintains this clamping performance across its specified operating temperature range, making it suitable for 48 V system protection where downstream components require strict voltage limiting.
Is the SMAJ43 suitable for bidirectional transient protection?
No, the SMAJ43 is a unidirectional TVS diode intended only for DC line protection with defined polarity. Its cathode band marking indicates the high-side connection point, and it does not provide symmetrical clamping in both directions. For bidirectional applications such as AC lines or data buses, a bipolar variant like SMAJ43CA must be used instead. The SMAJ43 datasheet explicitly states that electrical characteristics apply in one direction only, and using it in reverse-biased configuration beyond its specified VWM may result in premature failure.
What is the junction temperature limit and thermal derating behavior of the SMAJ43?
The SMAJ43 has a maximum junction temperature (TJ) of +150 °C and a storage temperature range of –55 °C to +150 °C. Its peak pulse power rating of 400 W is specified at TA = 25 °C and must be linearly derated above that ambient temperature per Figure 2 in the official datasheet. At 85 °C ambient, the usable PPPM drops to approximately 260 W. Proper PCB copper pour and thermal vias are recommended to maintain TJ within limits during repeated surge events. The SMAJ43's thermal performance is validated for automotive under-hood environments where sustained high ambient temperatures occur.
How does the SMAJ43 meet automotive EMC requirements?
The SMAJ43 is explicitly rated to meet ISO 7637-2 test pulses 1, 2a, 2b, 3a, and 3b - the core transient immunity standards for road vehicles. Its 400 W peak pulse power, fast <1.0 ps response, and controlled clamping voltage enable effective suppression of load-dump spikes (Pulse 5a/b), battery disconnect transients (Pulse 1), and alternator-induced surges (Pulse 2a/2b). When implemented with appropriate layout (short traces, low-inductance grounding), the SMAJ43 helps systems pass full vehicle-level EMC validation. The SMAJ43's qualification includes moisture sensitivity Level 1 per J-STD-020, supporting reflow compatibility in automotive manufacturing.
What packaging and reel options are available for the SMAJ43?
The SMAJ43 is supplied in DO-214AC (SMA) package format on 7,500-piece tape-and-reel carriers, optimized for high-speed pick-and-place assembly. Each reel includes standardized orientation with cathode band facing consistent direction, and the matte tin-plated leads comply with J-STD-002 solderability requirements. Lead-free and RoHS-compliant versions are standard. Aetrix Electronics provides full traceability including lot code, date code (YW format), and factory code (F) per reel, supporting automotive PPAP documentation and counterfeit mitigation for the SMAJ43.
SMAJ43 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):
- 43V
- Voltage - Breakdown (Min):
- 47.8V
- Voltage - Clamping (Max) @ Ipp:
- 76.7V
- Current - Peak Pulse (10/1000µs):
- 5.2A
- 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)
SMAJ43 FAQ
1.How can I place an order for SMAJ43 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ43 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 SMAJ43 reliable?
The price and inventory of SMAJ43 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ43 is usually 5 days.
3.What payment methods are accepted for SMAJ43?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ43 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ43?
SMAJ43 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ43 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 SMAJ43?
For technical support, including SMAJ43 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ43 requirements.
6.How does Aetrix verify that SMAJ43 is sourced from the original manufacturer or authorized distributors?
All SMAJ43 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 SMAJ43 meets industry standards.
7.What is the process for return or replacement of SMAJ43?
All SMAJ43 units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ43, 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 SMAJ43 part is unused and in its original packaging.
Return procedure for SMAJ43:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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