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Vishay General Semiconductor - Diodes Division SMAJ28AHE3_A/I
- Part No.:
- SMAJ28AHE3_A/I
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ28AHE3_A/I.pdf
- Description:
- TVS DIODE 28VWM 45.4VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:4,807
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Product details
Overview
SMAJ28AHE3_A/I from Vishay General Semiconductor is a unidirectional transient voltage suppressor (TVS) diode in SMA (DO-214AC) package, designed for robust overvoltage protection of sensitive electronics. It features a 28 V standoff voltage (VWM), 31.1–34.4 V breakdown voltage (VBR) at 1 mA, 45.4 V maximum clamping voltage (VC) at 8.8 A peak pulse current, and 400 W peak pulse power (10/1000 μs waveform). It is AEC-Q101 qualified and used to protect MOSFETs, ICs, and sensor signal lines in automotive and industrial power rails.
For engineers reviewing the SMAJ28AHE3_A/I datasheet, SMAJ28AHE3_A/I pinout, SMAJ28AHE3_A/I application, or SMAJ28AHE3_A/I equivalent, key selection criteria include clamping performance under 8.8 A surge, unidirectional polarity with cathode band marking, thermal resistance (RθJA = 120 °C/W), and AEC-Q101 qualification for automotive-grade reliability.
Technical Context
This TVS diode operates as a fast-acting shunt protector that clamps transient overvoltages above its breakdown threshold while maintaining low leakage (<1.0 μA at 28 V) during normal operation. Its glass-passivated junction ensures stable VBR tolerance and long-term reliability under repetitive surge stress.
The device responds in <1 ps to transients induced by inductive switching or ESD events, delivering precise clamping within 45.4 V at rated IPPM. Its SMA package supports automated SMT placement and meets MSL Level 1 (260 °C reflow peak), with matte tin-plated leads compliant to J-STD-002 and JESD 22-B102.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 28 V - Maximum continuous reverse operating voltage before conduction begins; defines safe working range for protected circuitry. |
| VBR (min/max) | 31.1 V / 34.4 V at IT = 1 mA - Confirmed breakdown window ensuring predictable turn-on behavior across production lots. |
| VC @ IPPM | 45.4 V at 8.8 A - Clamping voltage under standardized 10/1000 μs surge; determines maximum stress imposed on downstream components. |
| PPPM | 400 W - Peak pulse power handling capability; enables protection against high-energy transients like load dump or ISO 7637-2 pulses. |
| IFSM | 40 A - Non-repetitive forward surge current rating (8.3 ms half-sine); supports robustness against short-duration overcurrent events. |
| TJ max | +150 °C - Maximum junction temperature; allows operation in under-hood automotive environments and industrial enclosures. |
| RθJA | 120 °C/W - Thermal resistance junction-to-ambient on standard 0.2" × 0.2" copper pads; informs PCB thermal design requirements. |
Pinout & Package
Package: SMA (DO-214AC), surface-mount, low-profile case with cathode band marking on unidirectional variants. Dimensions: 4.93 mm × 3.99 mm × 2.29 mm (L × W × H), compatible with standard SMT pick-and-place equipment.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward current entry (unidirectional mode) | Connected to ground or low-side return path; forms shunt path during overvoltage events. |
| Cathode | Reverse-biased terminal (marked with band) | Connected to protected line (e.g., 28 V rail); conducts when transient exceeds VBR. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive applications including engine control units and body electronics per stress test requirements. |
| 400 W peak pulse power (10/1000 μs) | Handles high-energy transients such as ISO 7637-2 Pulse 1/2a/5a without degradation under specified duty cycle. |
| Glass passivated junction | Ensures stable VBR tolerance, low leakage drift over time, and resistance to humidity-induced parameter shift. |
| MSL Level 1 (260 °C peak) | Enables single-reflow assembly without moisture sensitivity concerns; eliminates bake-out requirement pre-assembly. |
| Matte tin-plated leads | Guarantees solderability per J-STD-002 and whisker resistance per JESD 201 Class 2 for long-term interconnect integrity. |
Applications
| Automotive Power Rail Protection | Industrial Sensor Interface Protection |
|---|---|
Use Scenario: Protecting 24 V supply lines in vehicle ECUs from load dump and alternator ripple transients. IC Role / Device Role / Timing Role: Shunt-type transient suppressor placed between power rail and ground, triggered within picoseconds of overvoltage onset. Use Value: Limits voltage excursion to ≤45.4 V during 8.8 A surges, preventing damage to microcontrollers and CAN transceivers powered from same rail. |
Use Scenario: Safeguarding analog output lines of pressure/temperature sensors in factory automation systems. IC Role / Device Role / Timing Role: Unidirectional clamp on sensor VOUT line referenced to system ground, absorbing ESD and cable discharge events. Use Value: Maintains signal integrity by clamping transients before they reach ADC inputs, with <1.0 μA leakage preserving measurement accuracy. |
| DC Motor Drive Circuit Protection | Telecom Power Supply Input Stage |
Use Scenario: Suppressing inductive kickback from brushed DC motors in robotics and actuation modules. IC Role / Device Role / Timing Role: Fast-response TVS placed across motor terminals or H-bridge outputs to divert flyback energy. Use Value: Withstands 40 A non-repetitive forward surge (8.3 ms), enabling reliable protection during frequent motor commutation cycles. |
Use Scenario: Front-end overvoltage protection for 28 V telecom rectifier outputs feeding base station subsystems. IC Role / Device Role / Timing Role: Primary clamping device on DC input bus, coordinated with upstream fuses and secondary filtering. Use Value: Delivers 400 W pulse power handling and +150 °C junction rating for uninterrupted operation in sealed outdoor enclosures. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ28A-E3/61 | Same electrical specs and SMA package, but commercial-grade (non-AEC-Q101) and supplied in 7" tape/reel (1800 pcs). | Lacks automotive qualification; suitable for industrial/commercial designs where AEC-Q101 is not mandated. | Select when cost sensitivity outweighs automotive compliance requirements and volume matches 7" reel format. |
| SMAJ28AHM3_A/I | Identical AEC-Q101 qualification and packaging, but halogen-free construction (per JEDEC J-STD-020) and RoHS-compliant. | Meets stricter environmental mandates (e.g., EU automotive OEMs requiring halogen-free BOMs). | Choose when regulatory compliance requires halogen-free materials without sacrificing electrical or thermal performance. |
Compared with SMAJ28AHE3_A/I, the SMAJ28A-E3/61 offers identical protection performance at lower cost but no automotive qualification, while SMAJ28AHM3_A/I provides equivalent AEC-Q101 reliability with halogen-free material compliance-critical for Tier 1 automotive supply chains.
Availability
SMAJ28AHE3_A/I is available at Aetrix Electronics and suitable for automotive power rail protection, industrial sensor interface hardening, and DC motor drive circuit safeguarding requiring stable component supply across multi-year production programs.
Supply support for SMAJ28AHE3_A/I 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
Vishay General Semiconductor is a global leader in discrete semiconductors, specializing in diodes, MOSFETs, optoelectronics, and passive components with emphasis on reliability and application-specific performance.
The SMAJ series was developed specifically for high-reliability transient suppression in harsh environments-including automotive, industrial, and telecom-balancing clamping precision, surge robustness, and manufacturability in compact surface-mount packages.
FAQ
What is the clamping voltage of SMAJ28AHE3_A/I at its rated peak pulse current?
The SMAJ28AHE3_A/I has a maximum clamping voltage (VC) of 45.4 V at its rated peak pulse current (IPPM) of 8.8 A, measured using the standardized 10/1000 μs waveform. This value defines the upper voltage limit imposed on protected circuitry during surge events and is confirmed per Vishay's datasheet revision 09-Jan-2024. The SMAJ28AHE3_A/I maintains this clamping performance across its qualified operating temperature range.
Is SMAJ28AHE3_A/I suitable for automotive applications?
Yes, SMAJ28AHE3_A/I is AEC-Q101 qualified, making it suitable for automotive applications including engine control units, body electronics, and infotainment power supplies. Its construction includes glass-passivated junctions, MSL Level 1 moisture sensitivity rating, and matte tin-plated leads compliant with JESD 201 Class 2 whisker testing-all verified per Vishay's qualification protocol. The SMAJ28AHE3_A/I meets the reliability demands of under-hood and cabin-mounted systems.
What does the "HE3" suffix indicate in SMAJ28AHE3_A/I?
The "HE3" suffix in SMAJ28AHE3_A/I denotes RoHS-compliant construction with AEC-Q101 qualification. Specifically, "H" indicates AEC-Q101 qualification, "E3" confirms RoHS compliance (lead-free, bromine-free), and the "_A/I" denotes packaging in 13" tape-and-reel format (7500 pcs). This distinguishes it from commercial-grade variants like SMAJ28A-E3/61 and halogen-free alternatives like SMAJ28AHM3_A/I.
How does SMAJ28AHE3_A/I differ from bidirectional TVS diodes like SMAJ28CA?
SMAJ28AHE3_A/I is unidirectional and features a cathode band for polarity identification, conducting only in reverse breakdown to protect positive-rail circuits. In contrast, SMAJ28CA is bidirectional with symmetrical clamping in both directions and no polarity marking. The SMAJ28AHE3_A/I offers lower leakage (<1.0 μA at 28 V) and is preferred for DC power line protection, whereas SMAJ28CA suits AC-coupled or dual-polarity signal lines where bidirectional clamping is required.
What is the thermal resistance of SMAJ28AHE3_A/I, and how does it affect PCB layout?
The SMAJ28AHE3_A/I has a typical junction-to-ambient thermal resistance (RθJA) of 120 °C/W when mounted on minimum recommended 0.2" × 0.2" (5.0 mm × 5.0 mm) copper pads per terminal. This value assumes standard FR-4 PCB construction and dictates minimum copper area needed to maintain TJ ≤ 150 °C under worst-case power dissipation. For higher ambient temperatures or repeated surges, increasing pad size or adding thermal vias improves heat dissipation and extends device lifetime. The SMAJ28AHE3_A/I's RθJA directly informs thermal design margins in automotive and industrial deployments.
SMAJ28AHE3_A/I Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Package/Case:
- DO-214AC, SMA
- Series:
- TransZorb®
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 28V
- Voltage - Breakdown (Min):
- 31.1V
- Voltage - Clamping (Max) @ Ipp:
- 45.4V
- Current - Peak Pulse (10/1000µs):
- 8.8A
- 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)
SMAJ28AHE3_A/I FAQ
1.How can I place an order for SMAJ28AHE3_A/I through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ28AHE3_A/I 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 SMAJ28AHE3_A/I reliable?
The price and inventory of SMAJ28AHE3_A/I are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ28AHE3_A/I is usually 5 days.
3.What payment methods are accepted for SMAJ28AHE3_A/I?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ28AHE3_A/I transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ28AHE3_A/I?
SMAJ28AHE3_A/I orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ28AHE3_A/I 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 SMAJ28AHE3_A/I?
For technical support, including SMAJ28AHE3_A/I datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ28AHE3_A/I requirements.
6.How does Aetrix verify that SMAJ28AHE3_A/I is sourced from the original manufacturer or authorized distributors?
All SMAJ28AHE3_A/I 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 SMAJ28AHE3_A/I meets industry standards.
7.What is the process for return or replacement of SMAJ28AHE3_A/I?
All SMAJ28AHE3_A/I units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ28AHE3_A/I, 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 SMAJ28AHE3_A/I part is unused and in its original packaging.
Return procedure for SMAJ28AHE3_A/I:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ28AHE3_A/I Tags
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