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Vishay General Semiconductor - Diodes Division SMAJ45AHE3_A/I
- Part No.:
- SMAJ45AHE3_A/I
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ45AHE3_A/I.pdf
- Description:
- TVS DIODE 45VWM 72.7VC DO214AC
- Quantity:
- Payment:
- Shipping:
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Product details
Overview
SMAJ45AHE3_A/I from Vishay General Semiconductor is a unidirectional transient voltage suppressor (TVS) diode designed for robust overvoltage protection of sensitive electronics. It features a 45 V standoff voltage (VWM), 50.0–55.3 V breakdown voltage (VBR) at 1 mA, and clamps transients to ≤72.7 V at 5.5 A peak pulse current (IPPM), delivering 400 W peak pulse power (10/1000 μs waveform). It is widely deployed in automotive power line and sensor interface protection where AEC-Q101 qualification and low clamping voltage are critical.
For engineers reviewing the SMAJ45AHE3_A/I datasheet, SMAJ45AHE3_A/I pinout, SMAJ45AHE3_A/I application, or SMAJ45AHE3_A/I equivalent, key selection criteria include its unidirectional polarity, SMA (DO-214AC) package with cathode band marking, AEC-Q101 qualification status, and verified clamping performance under repetitive surge conditions per IEC 61000-4-5.
Technical Context
This TVS diode operates as a fast-acting shunt clamp, responding in <1 ps to voltage transients exceeding its reverse standoff threshold. Its glass-passivated junction ensures stable leakage (<1.0 μA at 45 V) and long-term reliability under thermal cycling.
The device is rated for 40 A non-repetitive forward surge current (IFSM, 8.3 ms half-sine), supports operating junction temperatures from –55 °C to +150 °C, and meets MSL Level 1 per J-STD-020 with peak reflow at 260 °C - confirming suitability for high-volume automated SMT assembly.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 45 V - Maximum continuous reverse operating voltage before clamping initiates; defines safe signal/power rail margin. |
| VBR (min/max) | 50.0 V / 55.3 V at 1 mA - Confirmed breakdown range ensuring predictable turn-on across production lot and temperature. |
| VC @ IPPM | ≤72.7 V at 5.5 A - Clamping voltage under 10/1000 μs surge; determines maximum stress imposed on protected IC or MOSFET. |
| PPPM | 400 W - Peak pulse power handling capability; validates protection against ISO 7637-2 Pulse 1/2a/5a and IEC 61000-4-5 surges. |
| IFSM | 40 A - Single half-sine surge rating (8.3 ms); supports protection of 12 V automotive power inputs during load dump events. |
| TJ max | +150 °C - Maximum junction temperature; enables use in under-hood automotive modules without derating. |
| Package | SMA (DO-214AC) - Surface-mount outline with 5.28 mm × 4.50 mm footprint and 2.29 mm height; compatible with standard 0.2" × 0.2" copper pad layout. |
Pinout & Package
Package: SMA (DO-214AC), molded plastic case with matte tin-plated leads; cathode indicated by a visible band on the body. Mounting requires 0.2" × 0.2" (5.0 mm × 5.0 mm) copper pads per terminal for full 400 W rating.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Low-side reference node | Connected to circuit ground or low-impedance return path; completes clamping loop during transient events. |
| Cathode | Protected line input | Connected to the line being protected (e.g., 12 V supply rail or sensor signal); conducts surge current to ground when VIN > VBR. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive applications including engine control units, body electronics, and ADAS sensor interfaces. |
| 400 W peak pulse power (10/1000 μs) | Meets IEC 61000-4-5 Level 4 (4 kV) surge immunity requirements with margin for system-level testing. |
| Glass passivated junction | Ensures stable VBR and low leakage (<1.0 μA) over 15-year field life and extended temperature cycling. |
| MSL Level 1, 260 °C peak reflow | Enables single-pass lead-free reflow without moisture-related delamination or parametric shift. |
| Low incremental surge resistance | Minimizes voltage overshoot during fast-rising transients (e.g., ESD or inductive switch-off), improving protection fidelity. |
Applications
| Automotive Power Line Protection | Industrial Sensor Interface Protection |
|---|---|
|
Use Scenario: Protecting 12 V battery-fed ECUs from load dump and alternator ripple transients per ISO 7637-2. IC Role / Device Role / Timing Role: Shunt-clamp TVS placed between power rail and chassis ground; activates within picoseconds upon overvoltage detection. Use Value: Limits peak rail voltage to ≤72.7 V during 400 W surges, preventing damage to downstream DC-DC converters and microcontrollers. |
Use Scenario: Safeguarding analog sensor outputs (e.g., pressure, temperature) in factory automation PLC I/O modules. IC Role / Device Role / Timing Role: Unidirectional transient suppressor on signal lines referenced to local ground; absorbs coupling-induced spikes from nearby motor drives. Use Value: Maintains signal integrity by clamping transients to <73 V while adding <0.5 pF capacitance - negligible impact on 10 kHz sensor bandwidth. |
| Telecom Power Supply Input | Consumer USB Port ESD Protection |
|
Use Scenario: Secondary-side overvoltage suppression in AC/DC adapters powering PoE switches and base stations. IC Role / Device Role / Timing Role: Standoff-rated TVS on +5 V/+12 V output rails; triggered only during fault conditions (e.g., regulator failure). Use Value: Withstands 40 A surge (8.3 ms) without degradation, enabling compliance with UL 62368-1 fault energy limits. |
Use Scenario: Front-end protection for USB 2.0 data lines and VBUS in smart home hubs and portable chargers. IC Role / Device Role / Timing Role: Unidirectional clamp on VBUS line; blocks reverse current while suppressing ±15 kV contact ESD per IEC 61000-4-2. Use Value: Achieves <1.0 μA leakage at 45 V, preserving battery runtime; AEC-Q101 qualification ensures reliability in high-volume consumer manufacturing. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ45A-E3/61 | Same electrical specs and SMA package; RoHS-compliant commercial grade (non-AEC-Q101). | Lacks automotive qualification; suitable for industrial/commercial power supplies but not under-hood automotive. | Select when AEC-Q101 is not required and cost optimization is prioritized over automotive validation. |
| SMBJ45AHE3_A/I | Same VWM/VBR/VC ratings but in SMB (DO-214AA) package - 30 % larger footprint and 50 % higher thermal resistance (RθJA = 150 °C/W vs. 120 °C/W). | Lower power density; limited to ≤300 W peak pulse in same PCB layout due to reduced heat dissipation. | Choose only if existing PCB layout uses SMB pads or if higher surge current margin (>5.5 A) is needed with board-level heatsinking. |
Compared with SMAJ45AHE3_A/I, SMAJ45A-E3/61 offers identical protection performance without automotive qualification, while SMBJ45AHE3_A/I trades compactness for lower thermal efficiency - making SMAJ45AHE3_A/I optimal for space-constrained AEC-Q101 designs requiring full 400 W capability.
Availability
SMAJ45AHE3_A/I is available at Aetrix Electronics and suitable for automotive electronic control units, industrial sensor interfaces, and telecom power supply inputs requiring stable component supply with AEC-Q101 assurance and full traceability.
Supply support for SMAJ45AHE3_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, rectifiers, and protection devices with emphasis on reliability, precision, and automotive-grade validation.
The SMAJ series is engineered specifically for high-energy transient suppression in harsh environments - targeting automotive, industrial, and telecom systems where failure modes must be mitigated without compromising signal integrity or thermal performance.
FAQ
What is the clamping voltage of the SMAJ45AHE3_A/I under a 10/1000 μs surge?
The SMAJ45AHE3_A/I clamps to a maximum of 72.7 V at its rated peak pulse current of 5.5 A (10/1000 μs waveform), as specified in the Vishay datasheet revision 09-Jan-2024. This value is measured under standardized test conditions with 0.2" × 0.2" copper pads and confirms the device's ability to limit transient overvoltage stress on protected circuitry. The SMAJ45AHE3_A/I maintains this clamping performance across its full operating temperature range.
Is the SMAJ45AHE3_A/I qualified to AEC-Q101?
Yes, the SMAJ45AHE3_A/I is explicitly AEC-Q101 qualified, as confirmed by Vishay's ordering information table and product marking code "HE3". This qualification covers stress testing for temperature cycling, humidity bias, mechanical shock, and high-temperature operating life - validating its suitability for automotive applications such as body control modules and ADAS sensor interfaces. The SMAJ45AHE3_A/I carries the "HE3" suffix to distinguish it from commercial-grade variants like SMAJ45A-E3/61.
What is the standoff voltage (VWM) and why does it matter for SMAJ45AHE3_A/I?
The SMAJ45AHE3_A/I has a reverse standoff voltage (VWM) of 45 V - the maximum continuous DC or RMS voltage the device can block without entering conduction. This parameter ensures the SMAJ45AHE3_A/I remains non-conductive during normal operation of a 12 V or 24 V automotive system, minimizing leakage current (<1.0 μA) and avoiding false triggering. Selecting a VWM ≥110 % of nominal rail voltage prevents unnecessary power loss while maintaining headroom for ripple and tolerance.
Can SMAJ45AHE3_A/I be used in bidirectional configurations?
No, the SMAJ45AHE3_A/I is a unidirectional TVS diode, as indicated by its "A" suffix and cathode band marking. It conducts only in reverse bias above VBR and blocks forward current up to 3.5 V at 25 A. For bidirectional protection (e.g., AC lines or differential signals), the SMAJ45CA variant must be used - which has symmetrical breakdown in both directions and no polarity marking. Using SMAJ45AHE3_A/I in place of a bidirectional device would leave the forward-polarity transient unprotected.
What is the thermal resistance and maximum junction temperature of SMAJ45AHE3_A/I?
The SMAJ45AHE3_A/I has a typical junction-to-ambient thermal resistance (RθJA) of 120 °C/W when mounted on 0.2" × 0.2" copper pads, and a maximum operating junction temperature (TJ) of +150 °C. These values define its sustained power handling: at 25 °C ambient, it can dissipate up to 3.3 W continuously (PD rating), and its surge capability remains fully rated up to TJ = 150 °C. The SMAJ45AHE3_A/I's RθJA and TJ max enable reliable operation in sealed automotive enclosures without forced airflow.
SMAJ45AHE3_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):
- 45V
- Voltage - Breakdown (Min):
- 50V
- Voltage - Clamping (Max) @ Ipp:
- 72.7V
- Current - Peak Pulse (10/1000µs):
- 5.5A
- 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)
SMAJ45AHE3_A/I FAQ
1.How can I place an order for SMAJ45AHE3_A/I through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ45AHE3_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 SMAJ45AHE3_A/I reliable?
The price and inventory of SMAJ45AHE3_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 SMAJ45AHE3_A/I is usually 5 days.
3.What payment methods are accepted for SMAJ45AHE3_A/I?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ45AHE3_A/I transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ45AHE3_A/I?
SMAJ45AHE3_A/I orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ45AHE3_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 SMAJ45AHE3_A/I?
For technical support, including SMAJ45AHE3_A/I datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ45AHE3_A/I requirements.
6.How does Aetrix verify that SMAJ45AHE3_A/I is sourced from the original manufacturer or authorized distributors?
All SMAJ45AHE3_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 SMAJ45AHE3_A/I meets industry standards.
7.What is the process for return or replacement of SMAJ45AHE3_A/I?
All SMAJ45AHE3_A/I units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ45AHE3_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 SMAJ45AHE3_A/I part is unused and in its original packaging.
Return procedure for SMAJ45AHE3_A/I:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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