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Vishay General Semiconductor - Diodes Division SMAJ40CAHM3/H
- Part No.:
- SMAJ40CAHM3/H
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ40CAHM3/H.pdf
- Description:
- TVS DIODE 40VWM 64.5VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:2,930
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Product details
Overview
SMAJ40CAHM3/H from Vishay General Semiconductor is a bidirectional surface-mount Transient Voltage Suppressor (TVS) diode designed for robust overvoltage protection on signal and power lines. It features a 40 V standoff 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, and 400 W peak pulse power rating with 10/1000 μs waveform - deployed in automotive sensor interfaces, industrial I/O modules, and telecom line protection.
For engineers reviewing the SMAJ40CAHM3/H datasheet, SMAJ40CAHM3/H pinout, SMAJ40CAHM3/H application, or SMAJ40CAHM3/H equivalent, key selection criteria include bidirectional clamping symmetry, AEC-Q101 qualification status, halogen-free RoHS compliance (HM3 suffix), MSL Level 1 moisture sensitivity, and DO-214AC package thermal performance under repetitive surge conditions.
Technical Context
This TVS diode operates as a voltage-clamped shunt protector: during transient events exceeding VWM, it avalanches symmetrically in both directions to clamp voltage at ≤64.5 V while diverting up to 6.2 A (10/1000 μs). Its glass-passivated junction ensures stable breakdown characteristics and low leakage (<1.0 μA at 40 V).
Thermally, it delivers RθJA = 120 °C/W (typ.) on standard 0.2" × 0.2" copper pads and RθJL = 30 °C/W, enabling reliable operation up to TJ = +150 °C. The HM3 suffix confirms halogen-free, RoHS-compliant construction and AEC-Q101 qualification per Vishay's automotive-grade variant specification.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 40 V - Maximum continuous reverse operating voltage before clamping initiates; defines safe signal line bias margin. |
| VBR (min/max) | 44.4 V / 49.1 V at 1 mA - Confirmed bidirectional breakdown range; ensures consistent turn-on across polarity. |
| VC @ IPPM | 64.5 V at 6.2 A - Clamping voltage under 10/1000 μs surge; protects downstream ICs rated ≤65 V absolute max. |
| PPPM | 400 W - Peak pulse power handling (≤0.01% duty cycle); supports repeated lightning/ESD transients in industrial environments. |
| IFSM | 40 A - Non-repetitive forward surge current rating (8.3 ms half-sine); validates robustness against inductive switch-off spikes. |
| TJ max. | +150 °C - Maximum junction temperature; enables deployment in under-hood automotive or high-ambient industrial enclosures. |
| Package | SMA (DO-214AC) - Low-profile SMD outline (5.28 mm × 4.50 mm × 2.29 mm); compatible with automated pick-and-place and reflow. |
Pinout & Package
Package: SMA (DO-214AC), surface-mount, bidirectional - no polarity marking; symmetrical terminals.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode / Cathode (symmetrical) | Bidirectional transient conduction path | Either terminal serves as input/output; clamps voltage above ±64.5 V regardless of polarity - eliminates orientation concerns during layout. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive applications including engine control units and ADAS sensor interfaces per stress test requirements. |
| Halogen-free & RoHS-compliant (HM3) | Meets IEC 61249-2-21 and JEDEC J-STD-020 MSL Level 1; supports lead-free reflow and environmental compliance programs. |
| 400 W peak pulse power (10/1000 μs) | Handles IEC 61000-4-5 Level 4 surges (4 kV line-to-earth) without degradation when mounted per recommended pad layout. |
| Low clamping ratio (VC/VBR ≈ 1.37) | Minimizes let-through energy to protected circuitry - critical for safeguarding 3.3 V/5 V logic and analog front-ends. |
| Glass passivated junction | Ensures stable VBR tolerance (±5%), low leakage (<1 μA), and long-term reliability under thermal cycling. |
Applications
| Automotive Sensor Protection | Industrial PLC I/O Protection |
|---|---|
|
Use Scenario: Protecting CAN/FlexRay transceiver inputs and analog sensor outputs (e.g., pressure, temperature) from load-dump and ISO 7637-2 pulses. IC Role / Device Role / Timing Role: Bidirectional shunt clamping device placed directly at connector entry point to limit transient voltage before reaching interface IC. Use Value: Maintains signal integrity under 12 V/24 V system surges up to 400 W; AEC-Q101 qualification ensures field reliability in harsh automotive environments. |
Use Scenario: Safeguarding digital input channels on programmable logic controllers exposed to inductive kickback from solenoids and contactors. IC Role / Device Role / Timing Role: Fast-response voltage clamp on 24 V DC input lines, absorbing repetitive switching transients without thermal runaway. Use Value: Enables >100,000 surge cycles with <5% VC drift; DO-214AC footprint allows dense I/O module layouts with minimal PCB area. |
| Telecom Line Interface | Consumer Power Adapter ESD Protection |
|
Use Scenario: Shielding Ethernet PHY or RS-485 transceivers from lightning-induced surges on outdoor cabling in base station equipment. IC Role / Device Role / Timing Role: Primary-level TVS on differential pair lines, working in coordination with GDTs or secondary-stage suppressors. Use Value: Clamps common-mode surges to <65 V within <1 ns, preserving signal eye diagram integrity and meeting GR-1089-CORE immunity requirements. |
Use Scenario: Secondary-side overvoltage suppression on 5 V/9 V/12 V USB-C and barrel-jack power inputs in smart home hubs and audio devices. IC Role / Device Role / Timing Role: Final-stage protector after primary AC-DC conversion, guarding against plug-in surges and user-handling ESD. Use Value: Halogen-free HM3 construction satisfies IEC 62368-1 flammability and material content mandates; 400 W rating exceeds UL 1449 Type 4 requirements. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ40CAHE3/H | Same electrical specs and DO-214AC package; RoHS-compliant but not halogen-free (E3 vs HM3). | Lacks halogen-free certification; suitable for commercial/industrial use where material restrictions are less stringent. | Select SMAJ40CAHE3/H if AEC-Q101 is unnecessary and halogen-free compliance is not mandated by end-customer spec. |
| SMBJ40CAHM3 | Higher 600 W PPPM rating, same VWM/VC; larger SMB (DO-214AA) package (5.28 mm × 4.57 mm). | Offers greater surge margin but requires larger PCB footprint and higher thermal mass for equivalent cooling. | Choose SMBJ40CAHM3 only when system-level surge testing exceeds 400 W or when legacy designs already use SMB footprint. |
Compared with SMAJ40CAHE3/H, SMAJ40CAHM3/H adds halogen-free compliance and AEC-Q101 qualification without sacrificing clamping performance; versus SMBJ40CAHM3, it trades 200 W pulse headroom for 25% smaller board area and identical mounting process compatibility.
Availability
SMAJ40CAHM3/H is available at Aetrix Electronics and suitable for automotive sensor interfaces, industrial PLC I/O modules, and telecom line protection requiring stable component supply across multi-year production cycles.
Supply support for SMAJ40CAHM3/H 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 targets high-reliability transient suppression in automotive, industrial, and communications systems - engineered for fast response, stable clamping, and qualification-grade consistency under real-world surge stress.
FAQ
What does the "HM3" suffix indicate for SMAJ40CAHM3/H?
The HM3 suffix on SMAJ40CAHM3/H denotes halogen-free, RoHS-compliant construction and AEC-Q101 qualification. It confirms compliance with JEDEC J-STD-020 MSL Level 1, matte tin-plated leads solderable per J-STD-002, and whisker resistance per JESD 201 Class 2 - all verified for SMAJ40CAHM3/H in Vishay's official documentation.
Is SMAJ40CAHM3/H bidirectional, and how is polarity identified?
Yes, SMAJ40CAHM3/H is a bidirectional TVS diode - its "CA" suffix explicitly indicates symmetrical clamping in both directions. Unlike unidirectional variants, SMAJ40CAHM3/H has no cathode band or polarity marking; either terminal functions identically, simplifying PCB layout and eliminating orientation errors during assembly.
What is the maximum clamping voltage of SMAJ40CAHM3/H under surge conditions?
The maximum clamping voltage (VC) of SMAJ40CAHM3/H is 64.5 V at 6.2 A peak pulse current (IPPM) with a 10/1000 μs waveform. This value is measured and guaranteed per Vishay's datasheet (Document Number: 88390, Rev. 09-Jan-2024) and defines the upper voltage limit imposed on protected circuitry during transient events.
Can SMAJ40CAHM3/H replace SMAJ40A in a design?
No - SMAJ40CAHM3/H is bidirectional while SMAJ40A is unidirectional; they differ in polarity behavior, marking, and circuit role. SMAJ40A includes a cathode band and conducts only in reverse bias, whereas SMAJ40CAHM3/H clamps equally in both directions. Substitution requires schematic and layout review to ensure correct functionality and protection coverage.
What thermal derating applies to SMAJ40CAHM3/H above 25 °C ambient?
SMAJ40CAHM3/H follows Vishay's standard derating curve: peak pulse power decreases linearly above TA = 25 °C, reaching ~75% of 400 W at 75 °C and ~50% at 125 °C (per Fig. 2 in datasheet 88390). Its RθJA = 120 °C/W assumes minimum recommended 0.2" × 0.2" copper pads; actual board layout directly impacts usable surge margin.
SMAJ40CAHM3/H 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:
- -
- Bidirectional Channels:
- 1
- 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)
SMAJ40CAHM3/H FAQ
1.How can I place an order for SMAJ40CAHM3/H through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ40CAHM3/H 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 SMAJ40CAHM3/H reliable?
The price and inventory of SMAJ40CAHM3/H are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ40CAHM3/H is usually 5 days.
3.What payment methods are accepted for SMAJ40CAHM3/H?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ40CAHM3/H transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ40CAHM3/H?
SMAJ40CAHM3/H orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ40CAHM3/H 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 SMAJ40CAHM3/H?
For technical support, including SMAJ40CAHM3/H datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ40CAHM3/H requirements.
6.How does Aetrix verify that SMAJ40CAHM3/H is sourced from the original manufacturer or authorized distributors?
All SMAJ40CAHM3/H 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 SMAJ40CAHM3/H meets industry standards.
7.What is the process for return or replacement of SMAJ40CAHM3/H?
All SMAJ40CAHM3/H units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ40CAHM3/H, 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 SMAJ40CAHM3/H part is unused and in its original packaging.
Return procedure for SMAJ40CAHM3/H:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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