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Vishay General Semiconductor - Diodes Division SMAJ40AHM3_A/I
- Part No.:
- SMAJ40AHM3_A/I
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ40AHM3_A/I.pdf
- Description:
- TVS DIODE 40VWM 64.5VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:9,105
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Product details
Overview
SMAJ40AHM3_A/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 a 40 V stand-off voltage (VWM), 44.4–49.1 V breakdown voltage (VBR) at 1 mA, 64.5 V maximum clamping voltage (VC) at 6.2 A peak pulse current (IPPM), and 400 W peak pulse power rating with 10/1000 μs waveform - used to protect MOSFETs, ICs, and sensor interfaces in automotive and industrial power supplies.
For engineers reviewing the SMAJ40AHM3_A/I datasheet, SMAJ40AHM3_A/I pinout, SMAJ40AHM3_A/I application, or SMAJ40AHM3_A/I equivalent, key selection criteria include unidirectional polarity, AEC-Q101 qualification status, 150 °C max junction temperature, low incremental surge resistance, and compatibility with automated SMT placement on standard PCB copper pads.
Technical Context
The SMAJ40AHM3_A/I operates as a clamping-type TVS diode, entering avalanche conduction when reverse voltage exceeds its breakdown threshold (VBR), limiting transient energy by diverting surge current to ground. Its glass-passivated junction ensures stable leakage and fast response (<1 ns), while the SMA package provides thermal resistance of 120 °C/W (junction-to-ambient) and 30 °C/W (junction-to-lead).
Rated for repetitive 10/1000 μs surges at 0.01 % duty cycle, it delivers 400 W peak pulse power up to 78 V and derates to 300 W above that - validated under JEDEC J-STD-020 MSL Level 1 reflow conditions (peak 260 °C). Polarity is marked by cathode band; no marking on bidirectional variants.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 40 V - maximum continuous reverse operating voltage before clamping begins |
| VBR min/max | 44.4 V / 49.1 V at 1 mA - defines guaranteed avalanche onset range for design margining |
| VC @ IPPM | 64.5 V at 6.2 A - clamped voltage seen by protected circuit during full-rated surge |
| PPPM | 400 W (≤78 V), 300 W (>78 V) - peak transient energy handling per 10/1000 μs pulse |
| ID @ VWM | 1.0 μA - ultra-low reverse leakage preserves signal integrity and battery life |
| TJ max | +150 °C - enables operation in under-hood automotive and high-temperature industrial environments |
| Package | SMA (DO-214AC) - industry-standard SMT footprint compatible with IPC-7351B land patterns |
Pinout & Package
Package: SMA (DO-214AC), surface-mount, molded plastic case with matte tin-plated leads solderable per J-STD-002 and JESD 22-B102; polarity indicated by cathode band on unidirectional types.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward current entry / transient return path | Connected to protected line's low-side or ground reference; completes clamping loop during surge |
| Cathode | Reverse-biased clamping node | Connected to protected line's high-side; avalanche conduction initiates here when VWM exceeded |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive-grade reliability including temperature cycling, HTRB, and ESD robustness |
| Halogen-free & RoHS-compliant | Meets environmental compliance requirements for global electronics manufacturing and end-of-life disposal |
| 400 W peak pulse power | Handles IEC 61000-4-5 Level 4 surges (4 kV/2 Ω) without degradation when properly mounted |
| Low clamping ratio (VC/VBR ≈ 1.4) | Minimizes overvoltage stress on downstream ICs compared to higher-ratio suppressors |
| MSL Level 1 rating | Allows unlimited floor life and single-reflow processing at 260 °C peak without moisture-related failure |
Applications
| Automotive Power Rail Protection | Industrial Sensor Interface Protection |
|---|---|
Use Scenario: Protecting 12 V battery-fed ECUs against load dump and alternator transients per ISO 7637-2. IC Role / Device Role / Timing Role: Unidirectional TVS placed between power rail and chassis ground to clamp positive-going spikes above 40 V. Use Value: Limits transient voltage to ≤64.5 V, preventing damage to 36 V-rated DC-DC controllers and microcontrollers. | Use Scenario: Shielding analog sensor outputs (e.g., pressure, temperature) from ESD and cable discharge events. IC Role / Device Role / Timing Role: TVS connected across differential signal pair or from signal to ground to absorb ±8 kV contact ESD per IEC 61000-4-2. Use Value: Sub-1 ns response prevents latch-up in precision op-amps and ADC front-ends due to fast-rising transients. |
| Consumer Power Adapter Input Stage | Telecom Line Card Surge Protection |
Use Scenario: Safeguarding AC-DC adapter primary-side rectifier and controller ICs from lightning-induced surges. IC Role / Device Role / Timing Role: Mounted across bulk capacitor input to shunt line-to-line or line-to-ground transients before they reach switching FETs. Use Value: Withstands 40 A non-repetitive surge (IFSM) and maintains <1 μA leakage at 40 V, preserving no-load efficiency. | Use Scenario: Front-end protection for Ethernet PHYs and DSL line drivers exposed to induced surges on outdoor cabling. IC Role / Device Role / Timing Role: Unidirectional TVS applied between each data line and local ground plane to suppress common-mode transients. Use Value: Low capacitance (<100 pF at 0 V) avoids signal integrity degradation on 100 Mbps+ links while providing 64.5 V clamping. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ40AHE3_A/I | Same electrical specs; RoHS-compliant but not halogen-free; lacks HM3 suffix designation | Approved for commercial-grade automotive and industrial use, but not halogen-free supply chain requirement | Select when halogen-free material content is not mandated by OEM or regulatory specification |
| SMAJ40A-M3/61 | Identical TVS characteristics; differs only in packaging format (61 = 7" tape/reel, 1800 pcs) and base P/N suffix | No functional difference; intended for same PCB-level protection roles | Choose based on preferred reel size and volume procurement logistics, not performance or qualification |
Compared with SMAJ40AHM3_A/I, SMAJ40AHE3_A/I omits halogen-free certification but retains AEC-Q101 qualification, while SMAJ40A-M3/61 offers identical performance in a different tape-and-reel configuration - making HM3 the optimal choice where both automotive reliability and halogen-free compliance are required.
Availability
SMAJ40AHM3_A/I is available at Aetrix Electronics and suitable for automotive body control modules, industrial PLC I/O terminals, and telecom power supply designs requiring stable component supply with AEC-Q101 validation and halogen-free materials compliance.
Supply support for SMAJ40AHM3_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, TVS devices, and optoelectronics with emphasis on reliability, efficiency, and application-specific optimization.
The SMAJ series was developed for robust, surface-mount transient suppression in harsh environments - targeting automotive, industrial, and telecom systems where compact size, high surge capability, and qualification-grade consistency are critical.
FAQ
What is the clamping voltage of SMAJ40AHM3_A/I at its rated peak pulse current?
The SMAJ40AHM3_A/I has a maximum clamping voltage (VC) of 64.5 V at its rated peak pulse current (IPPM) of 6.2 A, measured using the standard 10/1000 μs double-exponential waveform. This value ensures protected circuits experience no more than 64.5 V during a full-rated transient event, directly supporting design margining for 36 V and 48 V system components. The SMAJ40AHM3_A/I achieves this with low dynamic impedance and fast avalanche response.
Is SMAJ40AHM3_A/I qualified for automotive applications?
Yes, SMAJ40AHM3_A/I is AEC-Q101 qualified, as confirmed by Vishay's ordering code structure (HM3 suffix denotes halogen-free + AEC-Q101). It undergoes stress testing including temperature cycling, high-temperature reverse bias, and ESD per AEC-Q101 Rev D. This makes SMAJ40AHM3_A/I suitable for under-hood and cabin ECU applications where reliability under thermal and electrical stress is mandatory.
What does the "HM3" suffix mean in SMAJ40AHM3_A/I?
The "HM3" suffix in SMAJ40AHM3_A/I indicates halogen-free, RoHS-compliant construction with AEC-Q101 qualification. "H" stands for halogen-free, "M3" confirms RoHS compliance and JESD201 Class 2 whisker resistance, and the "_A/I" denotes revision A in 13-inch tape-and-reel packaging (7500 units). This distinguishes it from E3 (RoHS only) and HE3 (RoHS + AEC-Q101, non-halogen-free) variants.
Can SMAJ40AHM3_A/I be used in bidirectional configurations?
No, SMAJ40AHM3_A/I is unidirectional - its cathode band marking and electrical specifications (e.g., forward voltage VF = 3.5 V at 25 A) confirm single-polarity operation. For bidirectional protection, Vishay specifies part numbers ending in "CA", such as SMAJ40CA. Using SMAJ40AHM3_A/I in reverse-biased signal paths without proper polarity alignment will result in unintended conduction or failure to clamp negative transients.
What is the thermal resistance of SMAJ40AHM3_A/I, and how does it affect PCB layout?
SMAJ40AHM3_A/I has a typical junction-to-ambient thermal resistance (RθJA) of 120 °C/W and junction-to-lead (RθJL) of 30 °C/W, measured on 0.2" × 0.2" copper pads. To maintain safe operation near its 150 °C max junction temperature, PCB layout must provide adequate copper area and minimize trace length to ground. Derating is required above 25 °C ambient - e.g., at 85 °C ambient, maximum power dissipation drops to ~1.7 W for continuous operation.
SMAJ40AHM3_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):
- 40V
- Voltage - Breakdown (Min):
- 44.4V
- Voltage - Clamping (Max) @ Ipp:
- 64.5V
- Current - Peak Pulse (10/1000µs):
- 6.2A
- 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)
SMAJ40AHM3_A/I FAQ
1.How can I place an order for SMAJ40AHM3_A/I through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ40AHM3_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 SMAJ40AHM3_A/I reliable?
The price and inventory of SMAJ40AHM3_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 SMAJ40AHM3_A/I is usually 5 days.
3.What payment methods are accepted for SMAJ40AHM3_A/I?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ40AHM3_A/I transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ40AHM3_A/I?
SMAJ40AHM3_A/I orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ40AHM3_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 SMAJ40AHM3_A/I?
For technical support, including SMAJ40AHM3_A/I datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ40AHM3_A/I requirements.
6.How does Aetrix verify that SMAJ40AHM3_A/I is sourced from the original manufacturer or authorized distributors?
All SMAJ40AHM3_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 SMAJ40AHM3_A/I meets industry standards.
7.What is the process for return or replacement of SMAJ40AHM3_A/I?
All SMAJ40AHM3_A/I units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ40AHM3_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 SMAJ40AHM3_A/I part is unused and in its original packaging.
Return procedure for SMAJ40AHM3_A/I:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ40AHM3_A/I Tags
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