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Vishay General Semiconductor - Diodes Division SMA5J18CAHM3/I
- Part No.:
- SMA5J18CAHM3/I
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMA5J18CAHM3/I.pdf
- Description:
- TVS DIODE 18VWM 29.2VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:5,515
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Product details
Overview
SMA5J18CAHM3/I from Vishay General Semiconductor is a bidirectional transient voltage suppressor (TVS) diode in SMA (DO-214AC) package, designed for high-energy surge protection on signal and power lines. It features a 18 V stand-off voltage (VWM), 20.0–22.1 V breakdown voltage (VBR), 500 W peak pulse power (PPPM), and clamps transients to ≤29.2 V at 17.1 A IPPM - used in automotive sensor interfaces, industrial I/O protection, and telecom line conditioning.
For engineers reviewing the SMA5J18CAHM3/I datasheet, SMA5J18CAHM3/I pinout, SMA5J18CAHM3/I application, or SMA5J18CAHM3/I equivalent, key selection criteria include bidirectional clamping capability, AEC-Q101 qualification (HM3 suffix), halogen-free RoHS compliance, and thermal resistance (RθJA = 80 °C/W) under PCB pad-limited dissipation.
Technical Context
This device operates as a voltage-clamped crowbar during ESD or lightning-induced surges, with symmetrical reverse/forward conduction due to its bidirectional construction. Its glass-passivated junction ensures stable VBR over temperature and long-term reliability under repetitive transients.
Designed for surface-mount automated assembly, it meets J-STD-020 MSL Level 1 (260 °C peak reflow) and JESD201 Class 2 whisker resistance. The SMA package provides low-profile mounting while maintaining 150 °C maximum junction temperature and 500 W 10/1000 μs surge handling.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 18 V - maximum continuous reverse operating voltage before clamping begins |
| VBR (min/max) | 20.0 V / 22.1 V at 1 mA - guaranteed breakdown threshold defining turn-on precision |
| VC @ IPPM | 29.2 V at 17.1 A - clamping voltage limiting downstream IC stress during 10/1000 μs surge |
| PPPM | 500 W - peak transient energy absorption capacity per single event |
| RθJA | 80 °C/W - thermal resistance from junction to ambient on standard 5 mm × 5 mm copper pads |
| TJ max. | +150 °C - maximum allowable junction temperature for sustained operation |
| Polarity | Bidirectional - symmetric clamping in both directions; no polarity marking required |
Pinout & Package
Package: SMA (DO-214AC), surface-mount, low-profile plastic case with matte tin-plated leads solderable per J-STD-002. No polarity marking on bidirectional variants like SMA5J18CAHM3/I.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode/Cathode (unmarked) | Surge current path | Both terminals function identically; bidirectional conduction enables placement without orientation check |
| Case (body) | Thermal interface | Plastic body transfers heat to PCB copper pads; no electrical connection |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified (HM3 suffix) | Validated for automotive-grade reliability including temperature cycling, HTRB, and ESD testing per AEC standard |
| Halogen-free & RoHS-compliant | Meets environmental compliance requirements for modern automotive and industrial electronics manufacturing |
| Low incremental surge resistance | Minimizes voltage overshoot during fast-rising transients (e.g., ISO 7637-2 pulse 1/2a/5a) |
| Very fast response time (<1 ps) | Clamps sub-nanosecond ESD events before sensitive circuitry sustains damage |
| MSL Level 1 rating | Allows direct placement into standard SMT reflow profiles without baking or dry-pack handling |
Applications
| Automotive Sensor Protection | Industrial PLC I/O Protection |
|---|---|
Use Scenario: Protecting CAN/LIN bus transceivers and analog sensor inputs (e.g., pressure, temperature) from load dump and inductive switching spikes in 12 V vehicle systems. IC Role / Device Role / Timing Role: Bidirectional TVS clamp placed directly at connector entry point to shunt surge energy before reaching signal conditioning ICs. Use Value: Maintains signal integrity under ISO 16750-2 load dump (up to 35 V, 100 ms) and ISO 7637-2 pulse 5a (75 V, 100 ms), preventing latch-up or permanent damage to microcontrollers. |
Use Scenario: Safeguarding digital input modules in programmable logic controllers exposed to field wiring transients from motor contactors and solenoids. IC Role / Device Role / Timing Role: Primary overvoltage suppression element on 24 V DC input channels, mounted adjacent to terminal block entry points. Use Value: Withstands repeated 500 W surges per IEC 61000-4-5 (10/1000 μs) without degradation, extending system uptime and reducing field failure rates. |
| Telecom Line Interface | Consumer Power Adapter Input |
Use Scenario: Surge protection on Ethernet PHY side of PoE-powered devices and DSL line drivers subjected to lightning-induced common-mode transients. IC Role / Device Role / Timing Role: Secondary-level TVS deployed after gas discharge tube (GDT) primary protection to limit let-through voltage to safe levels for PHY ICs. Use Value: Clamps residual surge to ≤29.2 V within nanoseconds, ensuring compliance with IEEE 802.3af/at robustness requirements and avoiding PHY reset or data corruption. |
Use Scenario: Input-stage transient suppression in AC/DC adapters for smart home hubs and IoT gateways connected to unconditioned mains outlets. IC Role / Device Role / Timing Role: First-line defense against differential-mode surges entering via AC input rectifier stage, placed across bulk capacitor terminals. Use Value: Absorbs 500 W single-event surges without thermal runaway, enabling compact adapter designs that meet UL 62368-1 and IEC 61000-4-5 Level 3 immunity. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMA5J18CAHE3/I | Same electrical specs; RoHS-compliant but not halogen-free; lacks AEC-Q101 qualification | Suitable for commercial/industrial use only; not approved for automotive under hood or chassis locations | Select when halogen-free requirement or automotive qualification is not mandated |
| SMB5J18CAHM3/I | Same VWM/VBR/PPPM; larger SMB (DO-214AA) package with higher RθJA (60 °C/W) and lower IFSM (100 A vs. 40 A) | Offers improved surge current margin but requires more PCB area; less suitable for space-constrained automotive modules | Choose when higher single-pulse surge margin is prioritized over board space and thermal performance |
Compared with SMA5J18CAHM3/I, SMA5J18CAHE3/I omits halogen-free and AEC-Q101 compliance - reducing cost but limiting automotive deployment; SMB5J18CAHM3/I trades compactness for higher surge current headroom and lower thermal resistance, making it preferable in high-reliability industrial power supplies.
Availability
SMA5J18CAHM3/I is available at Aetrix Electronics and suitable for automotive sensor interfaces, industrial PLC I/O protection, and telecom line conditioning requiring stable component supply across extended production lifecycles.
Supply support for SMA5J18CAHM3/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 and application-specific performance.
The SMA5J series is engineered for high-power-density transient suppression in harsh environments - targeting automotive, industrial, and telecom applications where AEC-Q101 qualification, halogen-free materials, and precise clamping are mandatory.
FAQ
What does the "HM3" suffix indicate in SMA5J18CAHM3/I?
The HM3 suffix in SMA5J18CAHM3/I denotes halogen-free, RoHS-compliant construction with full AEC-Q101 qualification. This means the device meets automotive reliability standards including temperature cycling, highly accelerated life testing, and electrostatic discharge immunity - critical for under-hood and chassis-mounted electronics where material safety and long-term stability are non-negotiable.
Is SMA5J18CAHM3/I suitable for protecting CAN FD bus lines?
Yes, SMA5J18CAHM3/I is appropriate for CAN FD protection due to its 18 V stand-off voltage matching typical 12 V automotive supply rails, bidirectional clamping symmetry, and sub-nanosecond response time. Its 29.2 V clamping voltage at 17.1 A ensures transceivers remain within safe operating limits during ISO 7637-2 pulse 4a (alternator load dump) and ESD events up to ±30 kV.
How does the thermal performance of SMA5J18CAHM3/I compare to similar TVS diodes in DO-214AC packages?
SMA5J18CAHM3/I has a typical junction-to-ambient thermal resistance (RθJA) of 80 °C/W when mounted on 5 mm × 5 mm copper pads - consistent with industry-standard DO-214AC TVS devices. This value enables reliable 500 W surge dissipation in short-duration events, though continuous power handling remains limited to ~0.625 W at 25 °C ambient without forced cooling.
Can SMA5J18CAHM3/I be used in place of a unidirectional TVS like SMA5J18A?
No - SMA5J18CAHM3/I is strictly bidirectional and lacks polarity marking, whereas SMA5J18A is unidirectional with cathode band identification. Substituting them requires verifying circuit topology: bidirectional use is mandatory for AC-coupled or floating signal lines, while unidirectional types are required for DC-biased rails where forward conduction must be blocked.
What is the maximum reverse leakage current for SMA5J18CAHM3/I at rated VWM?
At its 18 V stand-off voltage (VWM), SMA5J18CAHM3/I exhibits a maximum reverse leakage current (ID) of 1.0 μA at 25 °C, per the Vishay datasheet. This ultra-low leakage preserves signal integrity in high-impedance sensor interfaces and avoids unwanted loading on precision analog circuits such as bridge amplifiers or current-sense nodes.
SMA5J18CAHM3/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:
- 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):
- 17.1A
- Power - Peak Pulse:
- 500W
- 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)
SMA5J18CAHM3/I FAQ
1.How can I place an order for SMA5J18CAHM3/I through Aetrix?
Please submit a Request for Quotation (RFQ) for SMA5J18CAHM3/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 SMA5J18CAHM3/I reliable?
The price and inventory of SMA5J18CAHM3/I are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMA5J18CAHM3/I is usually 5 days.
3.What payment methods are accepted for SMA5J18CAHM3/I?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMA5J18CAHM3/I transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMA5J18CAHM3/I?
SMA5J18CAHM3/I orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMA5J18CAHM3/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 SMA5J18CAHM3/I?
For technical support, including SMA5J18CAHM3/I datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMA5J18CAHM3/I requirements.
6.How does Aetrix verify that SMA5J18CAHM3/I is sourced from the original manufacturer or authorized distributors?
All SMA5J18CAHM3/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 SMA5J18CAHM3/I meets industry standards.
7.What is the process for return or replacement of SMA5J18CAHM3/I?
All SMA5J18CAHM3/I units undergo pre-shipment inspection (PSI). If there is an issue with SMA5J18CAHM3/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 SMA5J18CAHM3/I part is unused and in its original packaging.
Return procedure for SMA5J18CAHM3/I:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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