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Vishay General Semiconductor - Diodes Division SMCJ18CAHM3/H
- Part No.:
- SMCJ18CAHM3/H
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SMCJ18CAHM3/H.pdf
- Description:
- TVS DIODE 18VWM 29.2VC DO214AB
- Quantity:
- Payment:
- Shipping:
Inventory:6,567
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Product details
Overview
SMCJ18CAHM3/H from Vishay General Semiconductor is a bidirectional transient voltage suppressor (TVS) diode in SMC (DO-214AB) package, designed for robust overvoltage protection of sensitive electronics. It features a 18 V standoff voltage (VWM), 20.0–22.1 V breakdown voltage (VBR at 1 mA), 1500 W peak pulse power (10/1000 µs), <1.0 µA reverse leakage at VWM, and clamps to ≤29.2 V at 51.4 A peak surge current - deployed on power rails and signal lines in automotive ECUs and industrial sensor interfaces.
For engineers reviewing the SMCJ18CAHM3/H datasheet, SMCJ18CAHM3/H pinout, SMCJ18CAHM3/H application, or SMCJ18CAHM3/H equivalent, this page delivers verified electrical parameters, AEC-Q101 qualification status, SMC package thermal data, and direct alternatives for ESD/surge protection design-in with halogen-free RoHS compliance.
Technical Context
This bidirectional TVS operates symmetrically across both polarities, enabling protection of AC-coupled or floating signal paths without polarity constraints. Its glass-passivated junction ensures stable clamping under repetitive transients, while low incremental surge resistance (<0.57 Ω derived from VC/IPPM) supports fast energy diversion during lightning-induced surges or inductive switching events.
The device meets MSL Level 1 per J-STD-020 with 260 °C lead-free reflow compatibility and is qualified to AEC-Q101 for automotive use - confirmed by HM3 suffix and "HM3_X" ordering code structure. Thermal resistance is 75 °C/W (junction-to-ambient) and 15 °C/W (junction-to-lead), defining PCB copper pad requirements for sustained 6.5 W power dissipation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 18 V - maximum continuous reverse operating voltage before clamping begins; defines safe operating margin for 12 V nominal systems. |
| VBR (min/max) | 20.0 V / 22.1 V at 1 mA - guaranteed breakdown threshold range; ensures consistent turn-on across production lots. |
| VC @ IPPM | ≤29.2 V at 51.4 A - clamped voltage during 10/1000 µs surge; determines protected circuit's maximum stress level. |
| PPPM | 1500 W - peak pulse power handling capability; validates immunity to IEC 61000-4-5 Level 4 surges (4 kV line-earth). |
| ID @ VWM | <1.0 µA - ultra-low reverse leakage; prevents measurable power loss or signal distortion in high-impedance circuits. |
| TJ max. | +150 °C - maximum junction temperature; enables operation in under-hood automotive environments. |
| Package | SMC (DO-214AB) - standardized surface-mount outline with 8.0 mm × 8.0 mm copper pads required for rated power derating. |
Pinout & Package
SMCJ18CAHM3/H uses the SMC (DO-214AB) package: a rectangular, surface-mount case with two coplanar matte tin-plated terminals. No polarity marking is present on bidirectional variants; both terminals are electrically symmetrical.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode/Cathode (bidirectional) | Surge current path | Both terminals conduct identically during positive or negative transients; no DC bias dependency. |
| Case | Thermal conduction path | Exposed metal slug transfers heat to PCB copper; requires minimum 8.0 mm × 8.0 mm pad per terminal for full 1500 W rating. |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional clamping | Enables single-device protection of AC signals, differential buses (e.g., CAN, RS-485), or ungrounded power domains without polarity concerns. |
| AEC-Q101 qualified (HM3) | Validated for automotive applications including engine control, ADAS sensors, and infotainment power supplies per stress test requirements. |
| Halogen-free & RoHS-compliant | Meets environmental compliance mandates for global OEMs; no brominated flame retardants in molding compound. |
| MSL Level 1 moisture sensitivity | Allows unlimited floor life and standard reflow without baking; compatible with high-volume automated SMT assembly. |
| Glass-passivated junction | Ensures long-term parameter stability and low leakage drift over temperature and lifetime, critical for safety-critical systems. |
Applications
| Automotive Power Rail Protection | Industrial Sensor Interface |
|---|---|
Use Scenario: Protecting 12 V battery-supplied microcontrollers and CAN transceivers from load dump and jump-start transients. IC Role / Device Role / Timing Role: Bidirectional TVS placed between VCC and GND to clamp voltage excursions above 29.2 V within nanoseconds. Use Value: Prevents latch-up or permanent damage to downstream ICs during ISO 7637-2 Pulse 5a (35 V/100 ms) events. | Use Scenario: Shielding analog outputs (4–20 mA) and digital I/O of PLC modules from field-wiring induced surges. IC Role / Device Role / Timing Role: Mounted directly at connector entry point to shunt transient energy before reaching precision ADC or isolator inputs. Use Value: Maintains signal integrity with <1.0 µA leakage, avoiding offset errors in µA-level current loops. |
| Telecom Line Interface | Consumer USB Port Protection |
Use Scenario: Safeguarding Ethernet PHYs and PoE injectors against lightning-induced common-mode surges on twisted-pair lines. IC Role / Device Role / Timing Role: Paired across differential pairs (e.g., TX+/TX−) to suppress mode conversion without affecting 100 MHz signal bandwidth. Use Value: Clamps to ≤29.2 V while exhibiting low junction capacitance (~200 pF at 0 V), minimizing signal attenuation. | Use Scenario: Adding secondary surge protection to USB 2.0 VBUS lines in smart home hubs exposed to accidental AC adapter misconnection. IC Role / Device Role / Timing Role: Placed upstream of USB power switch to absorb 1500 W surges before internal 5 V regulator fails. Use Value: Achieves IEC 61000-4-5 Level 4 compliance (4 kV) with no additional series impedance or filtering components. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ18CAHE3/A | Lower PPPM (400 W), SMA package (smaller thermal mass), same VWM/VBR range. | Restricted to lower-energy transients (e.g., ESD-only); unsuitable for IEC 61000-4-5 surges. | Select when board space is constrained and surge threat level is limited to human-body-model (HBM) or IEC 61000-4-2. |
| SMCJ18AHE3/H | Unidirectional variant; identical package, VWM, and PPPM, but cathode-marked and asymmetric conduction. | Requires correct polarity placement; cannot protect AC or floating nodes. | Choose only for DC-biased rails where reverse conduction is undesirable and polarity is fixed. |
Compared with SMCJ18CAHM3/H, SMAJ18CAHE3/A trades surge robustness for footprint reduction, while SMCJ18AHE3/H sacrifices bidirectional flexibility for marginally lower cost - making SMCJ18CAHM3/H the optimal choice for automotive and industrial designs demanding full-spectrum transient immunity without layout constraints.
Availability
SMCJ18CAHM3/H is available at Aetrix Electronics and suitable for automotive electronic control units, industrial programmable logic controllers, telecom infrastructure equipment, and consumer USB power delivery systems requiring stable component supply across extended product lifecycles.
Supply support for SMCJ18CAHM3/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, rectifiers, MOSFETs, and protection devices with emphasis on reliability and automotive-grade qualification.
The SMCJ family targets high-energy transient suppression in harsh environments, with design focus on AEC-Q101 compliance, low clamping voltage, and robust surge handling for power and signal line protection.
FAQ
What does the 'HM3' suffix indicate in SMCJ18CAHM3/H?
The 'HM3' suffix in SMCJ18CAHM3/H denotes halogen-free, RoHS-compliant construction with AEC-Q101 qualification. It confirms compliance with automotive reliability standards, absence of brominated flame retardants, and suitability for under-hood applications up to +150 °C junction temperature. This distinguishes SMCJ18CAHM3/H from commercial-grade M3 or E3 variants.
Is SMCJ18CAHM3/H bidirectional, and how does that affect circuit placement?
Yes, SMCJ18CAHM3/H is bidirectional - its electrical characteristics apply identically in both directions, with no polarity marking on the SMC package. This allows placement across any two nodes requiring symmetrical overvoltage protection, such as differential signal lines (CAN, RS-485), AC power inputs, or floating sensor grounds, eliminating orientation constraints during automated assembly.
What is the maximum clamping voltage of SMCJ18CAHM3/H, and why does it matter?
The maximum clamping voltage (VC) of SMCJ18CAHM3/H is 29.2 V at 51.4 A peak pulse current (10/1000 µs waveform). This value defines the highest voltage imposed on protected circuitry during a surge event; staying below the absolute maximum ratings of downstream ICs (e.g., 30 V tolerant CAN transceivers) ensures functional safety and prevents destructive overstress.
Does SMCJ18CAHM3/H require special PCB layout considerations?
Yes - SMCJ18CAHM3/H requires minimum 8.0 mm × 8.0 mm copper pads per terminal to achieve full 1500 W pulse power rating, as specified in Vishay's thermal derating curves. Smaller pads reduce surge capability significantly; additionally, short, wide traces to ground/power planes minimize inductance and preserve nanosecond response time during transient events.
How does SMCJ18CAHM3/H differ from unidirectional SMCJ18A variants?
SMCJ18CAHM3/H is bidirectional with symmetrical clamping in both polarities and no cathode band, whereas SMCJ18A variants are unidirectional, marked with a cathode band, and conduct only in reverse bias. The bidirectional version protects AC-coupled or floating circuits without polarity dependency, while the unidirectional type is restricted to DC rails with defined ground reference and offers slightly tighter VBR tolerance in one direction.
SMCJ18CAHM3/H 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/H FAQ
1.How can I place an order for SMCJ18CAHM3/H through Aetrix?
Please submit a Request for Quotation (RFQ) for SMCJ18CAHM3/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 SMCJ18CAHM3/H reliable?
The price and inventory of SMCJ18CAHM3/H are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMCJ18CAHM3/H is usually 5 days.
3.What payment methods are accepted for SMCJ18CAHM3/H?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMCJ18CAHM3/H transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMCJ18CAHM3/H?
SMCJ18CAHM3/H orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMCJ18CAHM3/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 SMCJ18CAHM3/H?
For technical support, including SMCJ18CAHM3/H datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMCJ18CAHM3/H requirements.
6.How does Aetrix verify that SMCJ18CAHM3/H is sourced from the original manufacturer or authorized distributors?
All SMCJ18CAHM3/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 SMCJ18CAHM3/H meets industry standards.
7.What is the process for return or replacement of SMCJ18CAHM3/H?
All SMCJ18CAHM3/H units undergo pre-shipment inspection (PSI). If there is an issue with SMCJ18CAHM3/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 SMCJ18CAHM3/H part is unused and in its original packaging.
Return procedure for SMCJ18CAHM3/H:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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