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Vishay General Semiconductor - Diodes Division SMCJ18CAHM3/I
- Part No.:
- SMCJ18CAHM3/I
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SMCJ18CAHM3/I.pdf
- Description:
- TVS DIODE 18VWM 29.2VC DO214AB
- Quantity:
- Payment:
- Shipping:
Inventory:9,154
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Product details
Overview
SMCJ18CAHM3/I from Vishay General Semiconductor is a bidirectional transient voltage suppressor (TVS) diode in SMC (DO-214AB) package, designed for high-energy surge protection with 1500 W peak pulse power rating, 18 V standoff voltage (VWM), and 29.2 V clamping voltage (VC) at 51.4 A peak pulse current. It protects sensitive signal lines and power rails in automotive sensor interfaces and industrial control I/O.
For engineers reviewing the SMCJ18CAHM3/I datasheet, SMCJ18CAHM3/I pinout, SMCJ18CAHM3/I application, or SMCJ18CAHM3/I equivalent, key selection criteria include bidirectional clamping capability, AEC-Q101 qualification, halogen-free RoHS compliance, and compatibility with 10/1000 µs surge waveforms per IEC 61000-4-5.
Technical Context
This TVS diode operates symmetrically in both directions due to its bidirectional construction, enabling protection of AC-coupled or differential signal paths without polarity constraints. Its glass-passivated junction ensures stable breakdown behavior and low leakage (<1.0 µA at VWM), while the SMC package supports automated placement and meets MSL Level 1 reflow requirements up to 260 °C.
The device delivers 1500 W peak pulse power dissipation under standardized 10/1000 µs transients, with thermal resistance of 75 °C/W (junction-to-ambient) and 15 °C/W (junction-to-lead). It is rated for continuous operation from −55 °C to +150 °C and qualified to AEC-Q101 for automotive under-hood applications.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 18 V - Maximum reverse operating voltage before clamping begins; defines safe working range for protected circuit. |
| VBR min/max | 20.0 V / 22.1 V - Breakdown occurs within this band at 1 mA test current; ensures predictable turn-on threshold. |
| VC @ IPPM | 29.2 V - Clamped voltage during 51.4 A 10/1000 µs surge; determines maximum stress on downstream components. |
| PPPM | 1500 W - Peak surge power handling capacity; enables robust protection against lightning-induced surges per IEC 61000-4-5. |
| IPPM | 51.4 A - Maximum non-repetitive surge current supported; defines survivability under defined transient conditions. |
| TJ max | +150 °C - Maximum junction temperature; allows operation in high-temperature automotive and industrial environments. |
| Package | SMC (DO-214AB) - Surface-mount outline with 8.0 mm × 8.0 mm copper pad thermal design; supports automated assembly and high-power dissipation. |
Pinout & Package
SMCJ18CAHM3/I uses the standard SMC (DO-214AB) package: a surface-mount, two-terminal device with no polarity marking for bidirectional operation. Terminals are matte tin-plated and solderable per J-STD-002 and JESD 22-B102.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Transient current entry (reverse bias) | One terminal of symmetrical PN junction; conducts during negative-going surges relative to cathode reference. |
| Cathode | Transient current entry (forward bias) | Second terminal of symmetrical PN junction; conducts during positive-going surges relative to anode reference. |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional clamping | Enables single-device protection of AC signals, differential buses (e.g., CAN, RS-485), and ungrounded power rails without polarity concerns. |
| AEC-Q101 qualification | Validated for automotive under-hood use including engine control units, body electronics, and ADAS sensor interfaces. |
| Halogen-free & RoHS-compliant | Meets environmental compliance requirements for global OEM supply chains and industrial equipment certifications. |
| Low incremental surge resistance | Minimizes voltage overshoot during fast-rising transients, improving protection margin for 3.3 V/5 V logic and microcontrollers. |
| MSL Level 1 moisture sensitivity | Allows unlimited floor life and standard reflow profiles up to 260 °C peak, simplifying manufacturing logistics. |
Applications
| Automotive Sensor Protection | Industrial I/O Interface |
|---|---|
Use Scenario: Protecting LIN/CAN bus nodes and analog sensor outputs (e.g., pressure, temperature) from load-dump and ISO 7637-2 pulses. IC Role / Device Role / Timing Role: Bidirectional voltage clamp placed across signal pair or between signal and ground. Use Value: Limits induced transients to ≤29.2 V, preventing damage to MCU GPIOs and analog front-end ICs rated for 30 V absolute maximum. | Use Scenario: Shielding PLC digital input modules and fieldbus transceivers from ESD and inductive switching noise in factory automation. IC Role / Device Role / Timing Role: Primary surge suppression element located at connector interface before signal conditioning circuitry. Use Value: Absorbs 1500 W surges without degradation, maintaining signal integrity and reducing false triggering in 24 V DC control systems. |
| Telecom Line Protection | Consumer Power Adapter Input |
Use Scenario: Safeguarding Ethernet PHYs and PoE injectors against lightning-induced surges on twisted-pair cabling. IC Role / Device Role / Timing Role: Common-mode and differential-mode transient suppressor mounted on RJ45 jack PCB footprint. Use Value: Symmetrical clamping ensures balanced protection across all four pairs, preserving signal skew and insertion loss specifications. | Use Scenario: Secondary-side overvoltage protection in AC/DC adapters for smart home devices and USB-C PD chargers. IC Role / Device Role / Timing Role: Standoff-rated clamp on 12–19 V DC output rail to prevent regulator latch-up during hot-plug events. Use Value: 18 V VWM allows normal operation while clamping to 29.2 V during 51.4 A surges, protecting downstream USB-PD controllers and battery management ICs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ18CAHM3/I | Lower PPPM (600 W), smaller SMB package, same VWM/VC ratings. | Suitable for space-constrained consumer electronics but not for high-energy industrial surges. | Select when board area is limited and surge energy is ≤600 W per IEC 61000-4-5 Level 3. |
| SMCJ18AHE3/I | Unidirectional version, identical package and VWM, but requires correct polarity orientation during layout. | Applicable only where circuit ground reference is fixed and reverse conduction must be blocked. | Choose only if system architecture mandates unidirectional blocking; otherwise SMCJ18CAHM3/I offers greater design flexibility. |
Compared with SMBJ18CAHM3/I and SMCJ18AHE3/I, the SMCJ18CAHM3/I provides higher surge robustness in a bidirectional configuration, eliminating polarity-dependent layout constraints while supporting full AEC-Q101 automotive qualification and halogen-free compliance.
Availability
SMCJ18CAHM3/I is available at Aetrix Electronics and suitable for automotive sensor interfaces, industrial PLC I/O modules, telecom line protection circuits, and consumer power adapter designs requiring stable component supply and long-term lifecycle support.
Supply support for SMCJ18CAHM3/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 SMCJ series is part of Vishay's TRANSZORB® TVS portfolio, engineered specifically for high-energy transient suppression in harsh environments including automotive, industrial, and telecommunications infrastructure.
FAQ
What does the 'CA' suffix indicate in SMCJ18CAHM3/I?
The 'CA' suffix in SMCJ18CAHM3/I denotes a bidirectional transient voltage suppressor. Unlike unidirectional variants (e.g., SMCJ18A), this device clamps voltage symmetrically in both polarities, making it ideal for protecting AC-coupled signals, differential buses like CAN or RS-485, and floating power rails where polarity cannot be guaranteed. The SMCJ18CAHM3/I achieves this using a back-to-back diode structure inside the SMC package.
Is SMCJ18CAHM3/I qualified for automotive applications?
Yes, SMCJ18CAHM3/I is AEC-Q101 qualified, as confirmed by Vishay's ordering code suffix 'HM3', which indicates halogen-free, RoHS-compliant, and AEC-Q101 qualified construction. This qualification validates its reliability under automotive temperature cycling, mechanical shock, and humidity testing, supporting use in engine control units, body electronics, and ADAS sensor modules per ISO/TS 16949 requirements.
How does the clamping voltage of SMCJ18CAHM3/I compare to its standoff voltage?
The SMCJ18CAHM3/I has a standoff voltage (VWM) of 18 V and a maximum clamping voltage (VC) of 29.2 V at 51.4 A. This 11.2 V margin ensures that protected ICs-such as 3.3 V or 5 V microcontrollers with 30 V absolute maximum ratings-remain within safe operating limits during surge events. The ratio VC/VWM ≈ 1.62 reflects optimized junction design for fast response and low overshoot.
What is the thermal performance of SMCJ18CAHM3/I in typical PCB layouts?
When mounted on 8.0 mm × 8.0 mm copper pads per Vishay's recommended layout, SMCJ18CAHM3/I achieves a junction-to-ambient thermal resistance (RθJA) of 75 °C/W and junction-to-lead resistance (RθJL) of 15 °C/W. This enables reliable operation at full 1500 W surge power without exceeding the +150 °C maximum junction temperature, provided ambient temperatures remain below 75 °C in continuous duty scenarios.
Can SMCJ18CAHM3/I replace older SMCJ18CA-E3 parts in existing designs?
Yes, SMCJ18CAHM3/I is a direct replacement for SMCJ18CA-E3 in most applications, with identical electrical specifications and SMC (DO-214AB) mechanical form factor. The HM3 suffix adds halogen-free material content and AEC-Q101 qualification, while maintaining compatibility with standard reflow profiles (MSL Level 1, 260 °C peak). No PCB layout changes are required, though designers should verify compliance requirements for new production lots.
SMCJ18CAHM3/I Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Package/Case:
- DO-214AB, SMC
- Series:
- TransZorb®
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Discontinued at Digi-Key
- Type:
- Zener
- Unidirectional Channels:
- -
- Bidirectional Channels:
- 1
- Voltage - Reverse Standoff (Typ):
- 18V
- Voltage - Breakdown (Min):
- 20V
- Voltage - Clamping (Max) @ Ipp:
- 29.2V
- Current - Peak Pulse (10/1000µs):
- 51.4A
- Power - Peak Pulse:
- 1500W (1.5kW)
- 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-214AB (SMC)
SMCJ18CAHM3/I FAQ
1.How can I place an order for SMCJ18CAHM3/I through Aetrix?
Please submit a Request for Quotation (RFQ) for SMCJ18CAHM3/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 SMCJ18CAHM3/I reliable?
The price and inventory of SMCJ18CAHM3/I are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMCJ18CAHM3/I is usually 5 days.
3.What payment methods are accepted for SMCJ18CAHM3/I?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMCJ18CAHM3/I transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMCJ18CAHM3/I?
SMCJ18CAHM3/I orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMCJ18CAHM3/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 SMCJ18CAHM3/I?
For technical support, including SMCJ18CAHM3/I datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMCJ18CAHM3/I requirements.
6.How does Aetrix verify that SMCJ18CAHM3/I is sourced from the original manufacturer or authorized distributors?
All SMCJ18CAHM3/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 SMCJ18CAHM3/I meets industry standards.
7.What is the process for return or replacement of SMCJ18CAHM3/I?
All SMCJ18CAHM3/I units undergo pre-shipment inspection (PSI). If there is an issue with SMCJ18CAHM3/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 SMCJ18CAHM3/I part is unused and in its original packaging.
Return procedure for SMCJ18CAHM3/I:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMCJ18CAHM3/I Tags
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DESD3V3E1BL-7B
Diodes Incorporated
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Diodes Incorporated
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Nexperia USA Inc.
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Toshiba Semiconductor and Storage
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Diodes Incorporated
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