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Taiwan Semiconductor Corporation SMAJ75
- Part No.:
- SMAJ75
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ75.pdf
- Description:
- 300W, 92.7V, 10%, UNIDIRECTIONAL
- Quantity:
- Payment:
- Shipping:
Inventory:3,224
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Product details
Overview
SMAJ75 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 75 V working stand-off voltage (VWM), 83.3–102 V breakdown voltage (VBR) at 1 mA test current, 134 V maximum clamping voltage (VC) at 3.0 A peak impulse current, and 400 W peak pulse power rating with 10/1000 µs waveform - suitable for automotive ISO 7637-2 Pulse 1/2a/2b/3a/3b compliance.
For engineers reviewing the SMAJ75 datasheet, SMAJ75 pinout, SMAJ75 application, or SMAJ75 equivalent, key selection criteria include clamping performance under 10/1000 µs transients, junction temperature derating above 25°C, DO-214AC (SMA) package thermal and layout constraints, and unidirectional polarity marking for correct PCB orientation.
Technical Context
The SMAJ75 operates as a silicon avalanche diode with glass-passivated junction, delivering sub-nanosecond response (<1.0 ps from 0 V to VBR min) and low leakage (<1 µA at 75 V). Its single-die DO-214AC construction supports automated placement and meets JESD201 Class 2 whisker resistance and J-STD-020 Level 1 moisture sensitivity.
It is rated for -55°C to +150°C operating junction temperature, 1 W steady-state power dissipation, and 40 A non-repetitive forward surge (8.3 ms half-sine). Clamping behavior follows standardized 10/1000 µs waveform per R.E.A., with peak power derated linearly above 25°C ambient per published curve.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 75 V - Maximum continuous reverse voltage before significant leakage; defines safe operating DC bus level. |
| VBR min/max | 83.3 V / 102 V @ 1 mA - Ensures reliable avalanche initiation across process variation and temperature. |
| VC @ IPPM | 134 V @ 3.0 A - Limits downstream circuit voltage during 10/1000 µs surge; critical for IC-level protection margin. |
| PPPM | 400 W (10/1000 µs) - Sustains high-energy transients without failure; derates to ~300 W above 78 V per spec. |
| IR @ VWM | <1 µA - Negligible standby power loss and minimal impact on high-impedance sensing nodes. |
| Package | DO-214AC (SMA) - Standardized surface-mount outline with cathode band marking; 0.060 g mass, UL 94V-0 molding. |
Pinout & Package
DO-214AC (SMA) package: molded plastic case with matte tin-plated leads, cathode indicated by a band on one end. Leads are solderable per J-STD-002; polarity must be observed during placement to ensure correct unidirectional clamping.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Low-side reference node | Connected to ground or low-voltage rail; forms clamping path when cathode is at higher potential. |
| Cathode | Protected line input | Connected to supply or signal line; clamps to anode when transient exceeds VBR; marked by band. |
Key Features
| Feature | Design Value |
|---|---|
| Glass-passivated junction | Enables stable, repeatable avalanche characteristics and long-term reliability under repeated surge stress. |
| Sub-1 ps response time | Activates before most fast transients (e.g., ESD, inductive kick) can damage downstream ICs. |
| ISO 7637-2 compliance | Validated for automotive load dump and switching transient immunity (Pulse 1/2a/2b/3a/3b). |
| Level 1 moisture sensitivity | Eliminates bake requirements prior to reflow; supports standard SMT assembly without special handling. |
Applications
| Switching Mode Power Supply (SMPS) | On-board DC/DC Converter |
|---|---|
Use Scenario: Protecting primary-side MOSFET gate drivers and secondary-side rectifier inputs against flyback spikes and cross-talk. IC Role / Device Role: Unidirectional TVS placed across input rails or between gate and source. Use Value: Limits clamped voltage to 134 V, preventing gate oxide rupture and ensuring >20 V margin below typical 150 V MOSFET VDS ratings. | Use Scenario: Safeguarding 12 V or 24 V input rails of point-of-load converters in industrial PLCs or telecom modules. IC Role / Device Role: Rail-to-rail clamping device on VIN pin to absorb coupled noise and hot-swap surges. Use Value: With 75 V VWM and 134 V VC, provides clean 12–24 V system compatibility while blocking normal operation and clamping faults. |
| Automotive Lighting Module | Adapter Input Protection |
Use Scenario: Suppressing load dump transients on LED driver inputs in headlamp control units per ISO 16750-2. IC Role / Device Role: Primary overvoltage clamp on battery-fed input stage. Use Value: Meets ISO 7637-2 Pulse 5a (load dump) with 400 W rating and 150°C TJ max, enabling under-hood deployment. | Use Scenario: Guarding AC/DC adapter outputs against backfeed, inrush, and lightning-induced surges. IC Role / Device Role: Output-side TVS to protect connected devices from adapter fault conditions. Use Value: 1 µA IR at 75 V ensures no measurable loading on regulated output; DO-214AC footprint fits compact adapter PCBs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ75A | Narrower VBR range (83.3–92.1 V); lower clamping voltage (121 V @ 3.3 A); tighter tolerance. | Better suited for systems requiring tighter clamping consistency and lower let-through voltage. | Select SMAJ75A when clamping precision and reduced overshoot are prioritized over absolute peak power margin. |
| P6SMB75A | Same DO-214AC package; 75 V VWM; 83.3–92.1 V VBR; 121 V VC @ 3.3 A; 600 W PPPM (10/1000 µs). | Higher peak power rating enables longer-duration or higher-energy transients. | Choose P6SMB75A where sustained surge energy exceeds 400 W but board space and footprint must remain identical. |
Compared with SMAJ75, SMAJ75A offers tighter VBR control and lower VC at slightly reduced peak current capability, while P6SMB75A delivers 50% higher peak power in the same package - making it preferable for harsher surge environments without layout change.
Availability
SMAJ75 is available at Aetrix Electronics and suitable for switching mode power supplies, automotive lighting modules, and on-board DC/DC converters requiring stable component supply, consistent surge performance, and RoHS-compliant manufacturing.
Supply support for SMAJ75 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 components.
The SMAJ series is part of TSC's transient suppression product line, engineered specifically for robust, high-reliability overvoltage protection in automotive, industrial, and consumer power systems with stringent AEC-Q200 alignment.
FAQ
What is the maximum clamping voltage of the SMAJ75 under standard test conditions?
The SMAJ75 has a maximum clamping voltage (VC) of 134 V when subjected to a 10/1000 µs waveform with a peak impulse current (IPPM) of 3.0 A. This value is measured at TA = 25°C and represents the upper limit of voltage seen by protected circuitry during a defined transient event. The SMAJ75 maintains this clamping performance across its specified operating temperature range, with minor derating above 25°C per the published pulse derating curve.
Is the SMAJ75 suitable for bidirectional transient protection?
No, the SMAJ75 is a unidirectional TVS diode and is not rated for bidirectional operation. Its electrical specifications apply only in the reverse-biased direction, with polarity clearly marked by a cathode band. For bidirectional protection, the SMAJ75C or SMAJ75CA variants must be used - these include internal back-to-back diode configuration and are explicitly designated for symmetric transient suppression in AC-coupled or floating signal lines.
What is the junction temperature rating for the SMAJ75, and how does it affect layout design?
The SMAJ75 has a maximum junction temperature (TJ) of +150°C and operates from -55°C to +150°C. To maintain reliability, PCB layout must provide adequate copper area and thermal vias to dissipate 1 W steady-state power and manage transient thermal spikes. Derating of peak pulse power begins above 25°C ambient, so thermal simulation or empirical testing is recommended for high-temperature environments such as under-hood automotive applications using the SMAJ75.
Does the SMAJ75 meet automotive industry standards for surge immunity?
Yes, the SMAJ75 meets ISO 7637-2 for automotive transient immunity, covering Pulse 1 (inductive load disconnect), Pulse 2a/2b (switching transients), and Pulse 3a/3b (capacitive coupling and ignition noise). While not AEC-Q200 qualified out-of-the-box, its construction - including glass-passivated junction, Level 1 moisture sensitivity, and 150°C TJ rating - aligns with key AEC-Q200 stress requirements, and it is widely deployed in automotive subsystems where full qualification is supported by system-level validation.
What packaging and reel options are available for the SMAJ75?
The SMAJ75 is supplied in DO-214AC (SMA) package format on 7,500-piece tape-and-reel carriers, compliant with EIA-481-D standards. Each reel includes full traceability data, RoHS and halogen-free certification documentation, and J-STD-020-compliant moisture barrier bagging. Custom reels, cut tapes, and tube options are available upon request for prototyping or low-volume production runs involving the SMAJ75.
SMAJ75 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):
- 75V
- Voltage - Breakdown (Min):
- 83.3V
- Voltage - Clamping (Max) @ Ipp:
- 134V
- Current - Peak Pulse (10/1000µs):
- 3A
- 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)
SMAJ75 FAQ
1.How can I place an order for SMAJ75 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ75 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 SMAJ75 reliable?
The price and inventory of SMAJ75 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ75 is usually 5 days.
3.What payment methods are accepted for SMAJ75?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ75 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ75?
SMAJ75 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ75 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 SMAJ75?
For technical support, including SMAJ75 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ75 requirements.
6.How does Aetrix verify that SMAJ75 is sourced from the original manufacturer or authorized distributors?
All SMAJ75 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 SMAJ75 meets industry standards.
7.What is the process for return or replacement of SMAJ75?
All SMAJ75 units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ75, 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 SMAJ75 part is unused and in its original packaging.
Return procedure for SMAJ75:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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