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Vishay General Semiconductor - Diodes Division SMAJ45AHM3/I
- Part No.:
- SMAJ45AHM3/I
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ45AHM3/I.pdf
- Description:
- TVS DIODE 45VWM 72.7VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:4,867
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Product details
Overview
SMAJ45AHM3/I from Vishay General Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode in SMA (DO-214AC) package, designed for clamping voltage transients up to 72.7 V at 5.5 A peak pulse current, with 400 W peak pulse power (10/1000 μs), 45 V stand-off voltage, and 50.0–55.3 V breakdown voltage range. It protects MOSFETs, ICs, and sensor signal lines in automotive and industrial power supply rails.
For engineers reviewing the SMAJ45AHM3/I datasheet, SMAJ45AHM3/I pinout, SMAJ45AHM3/I application, or SMAJ45AHM3/I equivalent, key selection criteria include its 45 V working voltage, 72.7 V clamping voltage at 5.5 A, AEC-Q101 qualification status, halogen-free RoHS compliance, and suitability for 12 V/24 V DC bus protection against load dump and inductive switching surges.
Technical Context
This TVS diode operates as a unidirectional clamping device with cathode-band polarity marking, leveraging a glass-passivated silicon junction for fast response (<1 ns) and low incremental surge resistance. Its thermal design relies on RθJA = 120 °C/W and RθJL = 30 °C/W, requiring minimum 0.2" × 0.2" copper pads per terminal for rated 400 W pulse handling.
The SMAJ45AHM3/I is rated for -55 °C to +150 °C operating junction temperature, supports 40 A non-repetitive forward surge (8.3 ms half-sine), and exhibits 0.102 %/°C temperature coefficient of breakdown voltage - enabling stable clamping across automotive ambient ranges.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Stand-off Voltage (VWM) | 45 V - maximum continuous reverse voltage before significant leakage; defines safe operating margin below clamping threshold |
| Breakdown Voltage (VBR) | 50.0–55.3 V at 1 mA - voltage at which device transitions from high-impedance to clamping conduction |
| Clamping Voltage (VC) | 72.7 V at 5.5 A (10/1000 μs) - peak voltage seen by protected circuit during surge; determines downstream component stress |
| Peak Pulse Power (PPPM) | 400 W - maximum transient energy absorption capability under standard 10/1000 μs waveform |
| Package | SMA (DO-214AC) - surface-mount package with 2.54 mm lead pitch, MSL Level 1, 260 °C reflow compatible |
| Qualification | AEC-Q101 qualified - validated for automotive-grade reliability including temperature cycling, HTRB, and ESD |
| Leakage Current (ID) | 1.0 μA max at 45 V - ensures minimal standby power loss and signal integrity in high-impedance circuits |
Pinout & Package
Package: SMA (DO-214AC), 2-terminal surface-mount case with molded epoxy body, matte tin-plated leads, and cathode band marking on unidirectional variants.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward current entry / Surge return path | Connected to system ground or low-side reference; carries full surge current during clamping event |
| Cathode | Reverse-biased terminal / Protected line connection | Connected to line being protected (e.g., 12 V rail); blocks 45 V DC but conducts above ~50 V breakdown |
Key Features
| Feature | Design Value |
|---|---|
| 400 W peak pulse power (10/1000 μs) | Enables robust protection against ISO 7637-2 Pulse 1, 2a, and 5a transients in 12 V automotive systems |
| AEC-Q101 qualification (HM3 suffix) | Confirms reliability for automotive powertrain, body control, and ADAS modules without additional qualification effort |
| Halogen-free & RoHS-compliant | Meets EU Directive 2011/65/EU and IPC-1752A material declarations for green manufacturing |
| Low profile SMA package | 0.208" × 0.157" footprint enables dense PCB layouts while maintaining thermal pad access for heatsinking |
| Fast response time (<1 ns) | Clamps transients before sensitive logic or analog circuitry sustains damage, preserving signal integrity |
Applications
| Automotive Power Supply Protection | Industrial Sensor Interface Protection |
|---|---|
Use Scenario: Protecting 12 V battery-fed ECUs from load dump (ISO 16750-2) and alternator overshoot. IC Role / Device Role / Timing Role: Unidirectional TVS placed between power rail and ground to clamp surges exceeding 45 V. Use Value: Limits voltage to ≤72.7 V during 400 W transients, preventing damage to 36 V-rated DC-DC converters and microcontrollers. | Use Scenario: Shielding 4–20 mA or CAN FD sensor lines from ESD (IEC 61000-4-2) and cable discharge events. IC Role / Device Role / Timing Role: Low-capacitance TVS shunting transients to ground while preserving signal bandwidth. Use Value: Sub-μA leakage at 45 V avoids loading precision current loops; fast clamping prevents latch-up in RS-485 transceivers. |
| Consumer Power Adapter Input Stage | Telecom DC Feeder Protection |
Use Scenario: Safeguarding AC/DC adapter primary-side rectifier outputs against lightning-induced surges on mains input. IC Role / Device Role / Timing Role: Secondary-side TVS absorbing residual transients after MOV/clamp stages. Use Value: 400 W rating handles coupled surges from 1.2/50 μs generator tests; 150 °C max junction temp supports enclosed thermal environments. | Use Scenario: Protecting -48 V telecom power feeds from accidental short-circuit recovery spikes and hot-swap transients. IC Role / Device Role / Timing Role: Unidirectional clamping device on negative rail to suppress positive-going transients relative to ground. Use Value: 45 V stand-off accommodates nominal -48 V with margin; 72.7 V clamping prevents overvoltage on -36 V tolerant PMICs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ45AHE3/I | Same electrical specs, RoHS-compliant but not halogen-free; no AEC-Q101 qualification | Restricted to commercial-grade industrial or consumer use; unsuitable for automotive production | Select when halogen-free content or automotive qualification is not required and cost sensitivity is higher |
| SMBJ45A-HM3 | Same VWM/VC, but SMB (DO-214AA) package - 20 % larger footprint, 600 W PPPM | Better surge handling for high-energy transients; requires PCB layout change due to larger pad dimensions | Choose when higher 600 W pulse rating is needed and board space allows SMB package |
Compared with SMAJ45AHE3/I, the SMAJ45AHM3/I adds halogen-free construction and AEC-Q101 validation for automotive deployment; versus SMBJ45A-HM3, it trades 200 W pulse capacity for 25 % smaller PCB area and identical mounting process compatibility.
Availability
SMAJ45AHM3/I is available at Aetrix Electronics and suitable for automotive electronics, industrial sensor interfaces, and telecom power feeders requiring stable component supply with full traceability and long-term lifecycle support.
Supply support for SMAJ45AHM3/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 is part of Vishay's TRANSZORB® TVS platform, engineered for high-speed transient suppression in harsh environments - particularly targeting automotive, industrial, and telecom infrastructure where repeatable clamping and AEC-Q101 compliance are mandatory.
FAQ
What is the clamping voltage of the SMAJ45AHM3/I at its rated peak pulse current?
The SMAJ45AHM3/I has a maximum clamping voltage (VC) of 72.7 V at 5.5 A peak pulse current under the standard 10/1000 μs waveform. This value is measured per JEDEC test conditions and defines the upper voltage limit imposed on protected circuitry during surge events. The SMAJ45AHM3/I maintains this clamping performance across its full operating temperature range (-55 °C to +150 °C) with minimal drift due to its 0.102 %/°C VBR coefficient.
Is the SMAJ45AHM3/I suitable for automotive applications?
Yes, the SMAJ45AHM3/I is AEC-Q101 qualified, as indicated by the "HM3" suffix, confirming its suitability for automotive applications including engine control units, body electronics, and ADAS subsystems. It meets requirements for temperature cycling, high-temperature reverse bias, and mechanical shock. The SMAJ45AHM3/I also complies with RoHS and is halogen-free, satisfying modern automotive material restrictions and environmental standards.
How does the SMAJ45AHM3/I differ from the SMAJ45A-E3 variant?
The SMAJ45AHM3/I differs from SMAJ45A-E3 in three key aspects: it uses halogen-free molding compound (vs. standard RoHS), carries AEC-Q101 qualification (vs. commercial grade only), and ships in 13" tape-and-reel packaging with "I" carrier code. Electrically, both share identical VWM, VBR, VC, and PPPM ratings. The SMAJ45AHM3/I is intended for automotive production, whereas SMAJ45A-E3 targets cost-sensitive commercial designs.
What is the thermal resistance of the SMAJ45AHM3/I, and how does it affect PCB layout?
The SMAJ45AHM3/I has a typical junction-to-ambient thermal resistance (RθJA) of 120 °C/W and junction-to-lead (RθJL) of 30 °C/W. To achieve rated 400 W pulse power, the datasheet specifies mounting on 0.2" × 0.2" (5.0 mm × 5.0 mm) copper pads per terminal. Reducing pad size increases thermal impedance, derating pulse capability - e.g., smaller pads may limit sustained surge handling to ≤300 W. Proper copper pour and via stitching beneath the SMA pads is recommended for thermal management.
Does the SMAJ45AHM3/I have polarity marking, and how is it oriented on the PCB?
Yes, the SMAJ45AHM3/I is unidirectional and features a visible cathode band at one end of the SMA (DO-214AC) package. During PCB layout, the banded end must be connected to the line being protected (e.g., +12 V rail), while the opposite (anode) terminal connects to system ground. Reversing polarity renders the device ineffective for overvoltage protection, as it will conduct continuously under normal bias. The SMAJ45AHM3/I's cathode-band orientation is consistent across all unidirectional SMAJ variants and matches standard diode placement conventions.
SMAJ45AHM3/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:
- Discontinued at Digi-Key
- 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:
- Telecom
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AC (SMA)
SMAJ45AHM3/I FAQ
1.How can I place an order for SMAJ45AHM3/I through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ45AHM3/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 SMAJ45AHM3/I reliable?
The price and inventory of SMAJ45AHM3/I are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ45AHM3/I is usually 5 days.
3.What payment methods are accepted for SMAJ45AHM3/I?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ45AHM3/I transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ45AHM3/I?
SMAJ45AHM3/I orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ45AHM3/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 SMAJ45AHM3/I?
For technical support, including SMAJ45AHM3/I datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ45AHM3/I requirements.
6.How does Aetrix verify that SMAJ45AHM3/I is sourced from the original manufacturer or authorized distributors?
All SMAJ45AHM3/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 SMAJ45AHM3/I meets industry standards.
7.What is the process for return or replacement of SMAJ45AHM3/I?
All SMAJ45AHM3/I units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ45AHM3/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 SMAJ45AHM3/I part is unused and in its original packaging.
Return procedure for SMAJ45AHM3/I:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ45AHM3/I Tags
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