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Vishay General Semiconductor - Diodes Division SMAJ550HM3_B/I
- Part No.:
- SMAJ550HM3_B/I
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ550HM3_B/I.pdf
- Description:
- TVS DIODE 495VWM 760VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:7,252
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Product details
Overview
SMAJ550HM3_B/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 on power and signal lines. It features 550 V breakdown voltage (VBR), 495 V working maximum voltage (VWM), 760 V clamping voltage at 400 mA, 300 W peak pulse power (10/1000 µs), and AEC-Q101 qualification for automotive use.
For engineers reviewing the SMAJ550HM3_B/I datasheet, SMAJ550HM3_B/I pinout, SMAJ550HM3_B/I application, or SMAJ550HM3_B/I equivalent, key selection criteria include unidirectional polarity, thermal resistance (RθJL = 30 °C/W), junction temperature range (–55 to +150 °C), low leakage (1.0 µA at VWM), and compliance with J-STD-020 MSL level 1.
Technical Context
This TVS diode operates as a fast-acting overvoltage protection device using an avalanche breakdown mechanism. Its unidirectional configuration protects against positive-going transients only, with a typical capacitance of 90 pF at 0 V and 7.5 pF at 200 V - suitable for high-speed data line protection where parasitic loading must be minimized.
The device's clamping behavior is defined by its incremental surge resistance and thermal design: RθJA = 120 °C/W (on standard PCB pads), enabling reliable operation up to TJ = 150 °C. Its 10/1000 µs waveform rating and 40 A IFSM support robust handling of inductive-switching surges common in automotive and industrial power rails.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VBR (min) | 550 V - ensures reliable triggering above system operating voltage (e.g., 48 V or 400 V bus with margin) |
| VWM | 495 V - maximum continuous reverse voltage before leakage exceeds 1.0 µA |
| VC @ 400 mA | 760 V - clamped voltage during 10/1000 µs transient, defining worst-case stress on downstream ICs |
| PPPM | 300 W - peak surge power handling capability under standardized transient waveform |
| IFSM | 40 A - non-repetitive forward surge current rating, critical for inrush or fault-current events |
| TJ max | +150 °C - maximum junction temperature, constraining PCB copper area and ambient derating |
| CJ @ 0 V | 90 pF - parasitic capacitance affecting high-frequency signal integrity on protected lines |
Pinout & Package
Package: SMA (DO-214AC), surface-mount, unidirectional polarity with cathode band marking. Matte tin-plated leads, RoHS-compliant and halogen-free, qualified to JESD 201 Class 2 whisker test and J-STD-020 MSL Level 1 (peak reflow 260 °C).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Current entry point during clamping | Connected to protected line (e.g., CAN_H, LIN, or 12 V rail); conducts when transient exceeds VBR |
| Cathode | Current exit point during clamping | Connected to ground or lower-potential reference; color band identifies this terminal on PCB layout |
Key Features
| Feature | Design Value |
|---|---|
| Glass passivated junction | Enables stable VBR and low leakage over temperature and lifetime |
| AEC-Q101 qualification | Validated for automotive-grade reliability including temperature cycling, HTRB, and ESD |
| Low incremental surge resistance | Minimizes VC overshoot during fast-rising transients (e.g., ISO 7637-2 Pulse 1/2a) |
| UL 94 V-0 molding compound | Ensures flame retardancy in enclosed automotive and industrial enclosures |
| Matte tin lead finish | Guarantees solderability per J-STD-002 and JESD 22-B102, supporting automated assembly |
Applications
| Automotive Power Rail Protection | Industrial Sensor Signal Line Protection |
|---|---|
Use Scenario: Protecting 12 V/24 V battery-fed ECUs from load-dump and jump-start transients per ISO 16750-2. IC Role / Device Role / Timing Role: Unidirectional TVS placed between power rail and chassis ground to clamp spikes up to ±100 V. Use Value: SMAJ550HM3_B/I's 760 V clamping voltage limits stress on downstream DC/DC converters and microcontrollers during 300 W surges. | Use Scenario: Shielding analog sensor outputs (e.g., pressure, temperature) from ESD and cable discharge events in factory automation. IC Role / Device Role / Timing Role: Low-capacitance TVS connected across differential pair or single-ended output to ground. Use Value: 90 pF capacitance at 0 V avoids signal distortion on 100 kHz–1 MHz sensor outputs while providing 15 kV HBM ESD immunity. |
| Telecom DC Power Input Protection | Consumer Device USB/Type-C Port Protection |
Use Scenario: Safeguarding 48 V PoE-powered equipment inputs against lightning-induced surges on outdoor cabling. IC Role / Device Role / Timing Role: Primary-level TVS on DC input stage upstream of DC/DC regulation and isolation. Use Value: 550 V VBR allows safe operation above 48 V nominal with headroom for ripple and tolerance, while 300 W PPPM meets IEC 61000-4-5 Level 3 requirements. | Use Scenario: Adding secondary-level surge protection on USB VBUS lines in portable docking stations or monitors. IC Role / Device Role / Timing Role: Unidirectional TVS between VBUS and GND to absorb hot-plug and ESD events without interfering with 5 V regulation. Use Value: 495 V VWM prevents conduction during normal operation, and 1.0 µA leakage preserves standby power budget. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ550A-M3/5A | Industrial grade (non-AEC-Q101), same VBR/VWM/VC, identical SMA package | Lacks automotive qualification; not suitable for vehicle ECU designs requiring AEC-Q101 | Select SMAJ550HM3_B/I when automotive qualification and traceable sourcing are required. |
| SMCJ550A-H | Higher PPPM = 1500 W, larger SMC (DO-214AB) package, same VBR/VWM | Requires more PCB area; used where higher surge energy (e.g., ISO 7637-2 Pulse 5a) must be absorbed | Choose SMAJ550HM3_B/I for space-constrained automotive modules needing AEC-Q101 and 300 W rating. |
Compared with SMAJ550A-M3/5A and SMCJ550A-H, the SMAJ550HM3_B/I uniquely combines AEC-Q101 qualification, SMA footprint, and 300 W surge capability - making it optimal for compact, automotive-grade power rail protection where board space and compliance are jointly constrained.
Availability
SMAJ550HM3_B/I is available at Aetrix Electronics and suitable for automotive electronic control units, industrial sensor interfaces, and telecom power input stages requiring stable component supply, full traceability, and long-term lifecycle support.
Supply support for SMAJ550HM3_B/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, MOSFETs, and protection devices with emphasis on reliability, efficiency, and application-specific performance.
The SMAJ series is engineered for robust transient suppression in harsh environments - targeting automotive, industrial, and telecom systems where failure due to voltage surges must be prevented without compromising size or thermal performance.
FAQ
What is the polarity configuration of the SMAJ550HM3_B/I?
The SMAJ550HM3_B/I is a unidirectional TVS diode, meaning it conducts only when the anode is more positive than the cathode by at least the breakdown voltage (550 V min). The cathode is marked by a color band on the SMA package body, and it must be connected toward the lower-potential side (e.g., ground) in circuit layout. This configuration protects against positive-going transients only.
Does the SMAJ550HM3_B/I meet automotive qualification standards?
Yes, the SMAJ550HM3_B/I is AEC-Q101 qualified, as confirmed by Vishay's documentation and ordering code suffix "HM3". This qualification covers stress tests including temperature cycling, high-temperature reverse bias (HTRB), and electrostatic discharge (ESD), making SMAJ550HM3_B/I suitable for use in automotive electronic control units, body electronics, and infotainment systems.
What is the clamping voltage of the SMAJ550HM3_B/I under standard test conditions?
The SMAJ550HM3_B/I has a maximum clamping voltage (VC) of 760 V when subjected to a 400 mA, 10/1000 µs double-exponential surge waveform. This value defines the upper voltage limit seen by downstream components during transient events and is measured with the device mounted on the minimum recommended PCB pad layout per Vishay's datasheet.
Can the SMAJ550HM3_B/I be used in bidirectional protection circuits?
No - the SMAJ550HM3_B/I is strictly unidirectional and cannot suppress negative-going transients. For bidirectional protection (e.g., AC lines or differential buses), a separate bidirectional TVS such as SMBJ550A or a back-to-back diode configuration would be required. Using SMAJ550HM3_B/I in reverse-biased configurations risks permanent damage due to lack of reverse breakdown specification.
What is the thermal resistance of the SMAJ550HM3_B/I, and how does it affect PCB layout?
The SMAJ550HM3_B/I has a typical junction-to-lead thermal resistance (RθJL) of 30 °C/W and junction-to-ambient (RθJA) of 120 °C/W when mounted on 0.2" × 0.2" copper pads. To maintain TJ ≤ 150 °C under 300 W pulses, designers must ensure adequate copper pour and avoid excessive trace length between the device and ground plane - especially critical in automotive under-hood applications.
SMAJ550HM3_B/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):
- 495V
- Voltage - Breakdown (Min):
- 550V
- Voltage - Clamping (Max) @ Ipp:
- 760V
- Current - Peak Pulse (10/1000µs):
- 400mA
- Power - Peak Pulse:
- 300W
- 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)
SMAJ550HM3_B/I FAQ
1.How can I place an order for SMAJ550HM3_B/I through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ550HM3_B/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 SMAJ550HM3_B/I reliable?
The price and inventory of SMAJ550HM3_B/I are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ550HM3_B/I is usually 5 days.
3.What payment methods are accepted for SMAJ550HM3_B/I?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ550HM3_B/I transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ550HM3_B/I?
SMAJ550HM3_B/I orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ550HM3_B/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 SMAJ550HM3_B/I?
For technical support, including SMAJ550HM3_B/I datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ550HM3_B/I requirements.
6.How does Aetrix verify that SMAJ550HM3_B/I is sourced from the original manufacturer or authorized distributors?
All SMAJ550HM3_B/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 SMAJ550HM3_B/I meets industry standards.
7.What is the process for return or replacement of SMAJ550HM3_B/I?
All SMAJ550HM3_B/I units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ550HM3_B/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 SMAJ550HM3_B/I part is unused and in its original packaging.
Return procedure for SMAJ550HM3_B/I:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ550HM3_B/I Tags
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