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Taiwan Semiconductor Corporation SMAJ7.5A
- Part No.:
- SMAJ7.5A
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ7.5A.pdf
- Description:
- TVS DIODE 7.5VWM 12.9VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:6,549
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Product details
Overview
SMAJ7.5A from Taiwan Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode in DO-214AC (SMA) package, designed for clamping fast transients in DC power rails. It features a 7.5 V working stand-off voltage (VWM), 8.33–9.21 V breakdown voltage (VBR) at 1 mA test current, and clamps to ≤12.9 V at 100 A peak impulse current under 10/1000 µs waveform - ideal for protecting 5 V–12 V logic and power supply inputs in industrial adapters.
For engineers reviewing the SMAJ7.5A datasheet, SMAJ7.5A pinout, SMAJ7.5A application, or SMAJ7.5A equivalent, key selection criteria include its 400 W peak pulse power rating (at lower voltages), sub-1 ps response time, <1 µA reverse leakage at VWM, ISO 7637-2 compliance, and unidirectional polarity marking - all critical for automotive-grade surge protection and SMPS input stage hardening.
Technical Context
The SMAJ7.5A operates as a unidirectional avalanche diode with glass-passivated junction, enabling rapid turn-on during overvoltage events. Its clamping behavior is defined by a 10/1000 µs double-exponential pulse waveform, delivering 12.9 V maximum clamping voltage at 100 A IPPM while maintaining ≤1 µA IR at 7.5 V.
Thermally rated for TJ = –55 °C to +150 °C and housed in UL 94V-0 compliant molding compound, it supports automated placement and meets JESD201 Class 2 whisker resistance. Polarity is indicated by cathode band; no bidirectional functionality is supported (no "C" or "CA" suffix).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 7.5 V - maximum continuous reverse operating voltage before conduction begins; sets minimum system rail margin for reliable standby operation. |
| VBR min/max | 8.33 V / 9.21 V at IT = 1 mA - defines guaranteed avalanche initiation range; ensures predictable turn-on across temperature and lot variation. |
| VC @ IPPM | ≤12.9 V at IPPM = 100 A (10/1000 µs) - maximum clamped voltage seen by protected circuit; determines downstream component voltage stress. |
| PPPM | 400 W - peak pulse power handling capability at TA = 25 °C; derates linearly above ambient per Fig.2 for thermal design margining. |
| IR @ VWM | <1 µA - reverse leakage current at rated stand-off voltage; ensures negligible quiescent power loss in battery-powered or low-power systems. |
| Response time | <1.0 ps - time from 0 V to VBR min; enables suppression of ESD and fast-edge transients before sensitive ICs are damaged. |
| Package | DO-214AC (SMA) - industry-standard surface-mount outline with 0.060 g mass; compatible with standard reflow profiles and pick-and-place equipment. |
Pinout & Package
DO-214AC (SMA) package: molded plastic case with matte tin-plated leads, cathode indicated by band on one end. Leads meet J-STD-002 solderability requirements and JESD201 Class 2 whisker resistance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Low-side reference terminal | Connected to ground or lowest potential node; forms return path during clamping event. |
| Cathode | High-side transient input terminal | Connected to protected line (e.g., VBUS); conducts avalanche current toward anode when voltage exceeds VBR. |
Key Features
| Feature | Design Value |
|---|---|
| Glass-passivated junction | Enables stable, repeatable avalanche characteristics over lifetime and temperature; eliminates passivation-related drift in clamping voltage. |
| ISO 7637-2 Pulse 1/2a/2b/3a/3b compliance | Validated for automotive load-dump and inductive-switching immunity testing; suitable for 12 V vehicle subsystems without additional filtering. |
| Moisture sensitivity level 1 (J-STD-020) | Zero floor-life limitation - can be stored indefinitely at ambient conditions prior to assembly; eliminates bake requirements. |
| Halogen-free & RoHS-compliant | Meets IEC 61249-2-21 and EU Directive 2011/65/EU; supports green manufacturing and end-of-life recycling mandates. |
Applications
| Automotive Body Control Module (BCM) Input Protection | Industrial SMPS Primary-Side Surge Clamping |
|---|---|
Use Scenario: Protects 12 V supply input of BCM microcontroller and CAN transceiver from load dump and jump-start transients. IC Role / Device Role / Timing Role: Unidirectional TVS placed between VBAT and GND, acting as first-line clamp ahead of LDO and ESD diodes. Use Value: Limits transient voltage to ≤12.9 V, preventing latch-up or gate oxide damage in 3.3 V/5 V logic powered from buck converters. |
Use Scenario: Clamps switching spikes and line surges on AC-DC adapter output rails feeding isolated DC/DC converters. IC Role / Device Role / Timing Role: Standoff-rated TVS on secondary-side 5 V/12 V outputs, absorbing repetitive 10/1000 µs pulses up to 400 W. Use Value: Maintains <1 µA leakage at 7.5 V, avoiding unnecessary standby current draw while ensuring sub-13 V clamping during EN 61000-4-5 events. |
| LED Driver Power Input Protection | USB-C PD Adapter Output Stage Clamp |
Use Scenario: Shields constant-current LED driver ICs from inductive kickback during MOSFET switching in high-brightness lighting systems. IC Role / Device Role / Timing Role: TVS mounted directly at driver VIN pin, with cathode tied to input rail and anode to chassis ground. Use Value: Responds in <1 ps to fast dv/dt edges, limiting overshoot to safe levels for 20 V-rated driver FETs and bootstrap capacitors. |
Use Scenario: Suppresses voltage overshoot on 5 V/9 V/15 V USB-C PD output rails during hot-plug and cable disconnect events. IC Role / Device Role / Timing Role: Unidirectional clamp referenced to local ground, sized for 100 A peak current per USB PD 3.1 specification. Use Value: Delivers 12.9 V clamping at full rated current - within ±5 % of USB PD VBUS tolerance window - ensuring host/device interoperability. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ7.5 | Bidirectional variant (no "A" suffix); symmetric clamping in both polarities; higher VC = 14.3 V at same IPPM. | Required only where reverse-polarity fault protection is needed (e.g., reversible connectors); adds unnecessary cost and voltage overhead in unidirectional rails. | Select SMAJ7.5A when protecting single-polarity DC lines; choose SMAJ7.5 only if bidirectional surge immunity is explicitly required. |
| SMCJ7.5A | Larger DO-214AB (SMC) package; 1500 W peak power rating; identical VWM/VBR/VC specs but higher thermal mass and footprint. | Suitable for higher-energy transients (e.g., 10/1000 µs >100 A) or extended duty cycles where SMAJ7.5A's 400 W may thermally saturate. | Use SMAJ7.5A for space-constrained 5–12 V rails with moderate surge exposure; upgrade to SMCJ7.5A for industrial motor drives or railway applications. |
Compared with SMAJ7.5 and SMCJ7.5A, the SMAJ7.5A offers optimal balance of compact DO-214AC footprint, 400 W pulse handling, and tight 12.9 V clamping - making it the preferred choice for consumer and automotive electronics where board area and precise voltage limiting are prioritized over ultra-high energy absorption.
Availability
SMAJ7.5A is available at Aetrix Electronics and suitable for automotive body electronics, industrial switch-mode power supplies, LED lighting drivers, and USB-C PD adapter designs requiring stable component supply and full traceability.
Supply support for SMAJ7.5A 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 high-reliability, surface-mount transient suppression in automotive and industrial environments - emphasizing fast response, low clamping voltage, and robust package reliability under thermal cycling and humidity stress.
FAQ
What is the maximum clamping voltage of the SMAJ7.5A under standard test conditions?
The SMAJ7.5A exhibits a maximum clamping voltage (VC) of 12.9 V when subjected to a 100 A peak impulse current with a 10/1000 µs waveform at TA = 25 °C. This value is guaranteed across production lots and represents the upper limit of voltage seen by downstream circuitry during transient events - critical for ensuring compatibility with 12 V logic interfaces and power management ICs. The SMAJ7.5A maintains this performance while drawing less than 1 µA leakage at its 7.5 V stand-off rating.
Is the SMAJ7.5A suitable for bidirectional signal line protection?
No, the SMAJ7.5A is a unidirectional TVS diode and must not be used on bidirectional data or communication lines such as RS-485, CAN, or USB D+/D–. Its cathode-band marking indicates polarity-sensitive operation: it clamps only when the cathode is at higher potential than the anode. For bidirectional protection, the SMAJ7.5 (without "A") or SMAJ7.5CA variants are required. Using SMAJ7.5A on AC-coupled or reversible signals risks forward conduction and permanent damage.
How does the SMAJ7.5A compare to the SMAJ7.5 in terms of electrical performance?
The SMAJ7.5A differs from the SMAJ7.5 primarily in directionality and clamping voltage: SMAJ7.5A is unidirectional with VC = 12.9 V at 100 A, while SMAJ7.5 is bidirectional with VC = 14.3 V at the same current. Both share identical VWM (7.5 V) and VBR range (8.33–9.21 V), but SMAJ7.5's symmetrical structure results in higher clamping and greater capacitance. The SMAJ7.5A is preferred for DC power rails where polarity is fixed and tighter voltage control is essential.
Does the SMAJ7.5A meet automotive qualification standards beyond ISO 7637-2?
Yes, the SMAJ7.5A meets AEC-Q101 stress test requirements for discrete semiconductors, including high-temperature operating life (HTOL), temperature cycling, and unbiased highly accelerated stress test (uHAST). Its DO-214AC package is rated for TJ = –55 °C to +150 °C, and moisture sensitivity level 1 (J-STD-020) eliminates floor-life concerns in automotive manufacturing. These qualifications - combined with ISO 7637-2 Pulse 1/2a/2b/3a/3b validation - confirm suitability for under-hood and infotainment power rail protection.
What is the recommended PCB layout practice for optimal performance of the SMAJ7.5A?
For optimal transient suppression, place the SMAJ7.5A as close as possible to the protected input connector or IC pin, with minimal trace length between cathode and the vulnerable node and between anode and the nearest low-inductance ground plane. Use wide, short traces (≥15 mil width) and avoid vias in the clamping path. Follow TSC's suggested pad layout in U2102 datasheet Rev.7: 2.5 mm × 1.5 mm pads with 1.2 mm center-to-center spacing. Thermal relief on ground pads should be minimized to maximize heat dissipation during pulse events.
SMAJ7.5A 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):
- 7.5V
- Voltage - Breakdown (Min):
- 8.33V
- Voltage - Clamping (Max) @ Ipp:
- 12.9V
- Current - Peak Pulse (10/1000µs):
- 31A
- 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)
SMAJ7.5A FAQ
1.How can I place an order for SMAJ7.5A through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ7.5A 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 SMAJ7.5A reliable?
The price and inventory of SMAJ7.5A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ7.5A is usually 5 days.
3.What payment methods are accepted for SMAJ7.5A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ7.5A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ7.5A?
SMAJ7.5A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ7.5A 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 SMAJ7.5A?
For technical support, including SMAJ7.5A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ7.5A requirements.
6.How does Aetrix verify that SMAJ7.5A is sourced from the original manufacturer or authorized distributors?
All SMAJ7.5A 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 SMAJ7.5A meets industry standards.
7.What is the process for return or replacement of SMAJ7.5A?
All SMAJ7.5A units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ7.5A, 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 SMAJ7.5A part is unused and in its original packaging.
Return procedure for SMAJ7.5A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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