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Vishay General Semiconductor - Diodes Division SMCJ20CAHM3/I
- Part No.:
- SMCJ20CAHM3/I
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SMCJ20CAHM3/I.pdf
- Description:
- TVS DIODE 20VWM 32.4VC DO214AB
- Quantity:
- Payment:
- Shipping:
Inventory:2,590
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Product details
Overview
SMCJ20CAHM3/I from Vishay General Semiconductor is a bidirectional surface-mount Transient Voltage Suppressor (TVS) diode in SMC (DO-214AB) package, designed for clamping voltage transients up to 1500 W peak pulse power with a 10/1000 µs waveform, 32.4 V maximum clamping voltage at 46.3 A peak pulse current, and 20 V stand-off voltage - deployed across automotive sensor signal lines, industrial I/O protection, and telecom interface circuits.
For engineers reviewing the SMCJ20CAHM3/I datasheet, SMCJ20CAHM3/I pinout, SMCJ20CAHM3/I application, or SMCJ20CAHM3/I equivalent, this page delivers verified electrical parameters, AEC-Q101 qualification status, thermal resistance data, junction capacitance behavior, and real-world design implications for surge immunity in 12 V–24 V systems.
Technical Context
The SMCJ20CAHM3/I operates as a bidirectional avalanche diode, symmetrically clamping both positive and negative transients above its breakdown voltage range of 22.2 V to 24.5 V at 1 mA test current. Its low incremental surge resistance enables fast response to ESD and lightning-induced surges while maintaining stable clamping under repetitive stress.
Designed for PCB-level protection without series impedance, it features glass-passivated junctions, meets MSL Level 1 per J-STD-020, and supports lead-free reflow up to 260 °C peak. The halogen-free, RoHS-compliant HM3 suffix confirms AEC-Q101 qualification for automotive-grade reliability.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 20 V - Maximum continuous reverse operating voltage before clamping begins; sets usable DC bias margin in 24 V rail protection. |
| VBR min/max | 22.2 V / 24.5 V at 1 mA - Confirmed breakdown threshold ensures predictable turn-on during overvoltage events. |
| VC @ IPPM | 32.4 V at 46.3 A - Clamping voltage under full 1500 W surge defines worst-case voltage seen by downstream ICs. |
| PPPM | 1500 W - Peak pulse power rating with 10/1000 µs waveform; validates robustness against IEC 61000-4-5 Level 4 surges. |
| RθJA | 75 °C/W - Junction-to-ambient thermal resistance on standard 8 mm × 8 mm copper pads; informs derating above 25 °C ambient. |
| TJ max | +150 °C - Maximum junction temperature allows operation in under-hood automotive environments. |
| Package | SMC (DO-214AB) - Surface-mount outline with 7.75 mm × 6.22 mm footprint and 2.62 mm height; compatible with automated placement. |
Pinout & Package
SMCJ20CAHM3/I uses the SMC (DO-214AB) package: a two-terminal, bidirectional device with no polarity marking. Terminals are matte tin-plated leads solderable per J-STD-002 and JESD 22-B102, mounted on 0.31" × 0.31" (8.0 mm × 8.0 mm) copper pads per terminal.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Transient return path (bidirectional) | Acts as cathode during positive transients and anode during negative transients; symmetrical conduction enables AC line or differential signal protection. |
| Cathode | Transient return path (bidirectional) | Electrically identical to Anode in bidirectional configuration; no band marking distinguishes terminals. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive applications including engine control modules and ADAS sensor interfaces requiring lifetime reliability under thermal cycling and vibration. |
| Halogen-free & RoHS-compliant (HM3) | Meets global environmental compliance mandates without compromising surge performance or thermal stability. |
| 1500 W peak pulse power | Supports IEC 61000-4-5 surge immunity up to 4 kV (line-earth) and 2 kV (line-line) in industrial PLC I/O stages. |
| Low clamping ratio (VC/VWM = 1.62) | Minimizes overvoltage stress on protected ICs - critical for 3.3 V or 5 V logic interfacing with 24 V field wiring. |
| MSL Level 1 moisture sensitivity | Enables direct placement without baking; eliminates production delays in high-volume SMT assembly lines. |
Applications
| Automotive Sensor Protection | Industrial PLC Analog Input |
|---|---|
Use Scenario: Protecting CAN/LIN bus transceivers and temperature/pressure sensors in engine compartments exposed to load dump and ISO 7637-2 pulses. IC Role / Device Role / Timing Role: Bidirectional TVS clamping transient energy before it reaches the sensor signal conditioning circuitry. Use Value: Maintains signal integrity during 12 V battery transients up to ±300 V/50 ms, preventing latch-up or permanent damage to 5 V analog front-ends. | Use Scenario: Shielding 4–20 mA current loop inputs in programmable logic controllers from induced surges on factory floor wiring. IC Role / Device Role / Timing Role: Fast-acting voltage clamp placed across input terminals to shunt surge current away from precision op-amps and ADCs. Use Value: Limits voltage excursion to ≤32.4 V during 1 kV/500 A surge events, preserving measurement accuracy and enabling Class I/II isolation compliance. |
| Telecom Ethernet PHY Interface | Consumer Appliance Motor Control |
Use Scenario: Safeguarding 10/100BASE-TX Ethernet PHYs in networked appliances against ESD and cable discharge events. IC Role / Device Role / Timing Role: Low-capacitance bidirectional TVS placed on differential pairs to suppress common-mode transients without distorting signal edges. Use Value: Delivers <10 pF junction capacitance at zero bias, ensuring minimal impact on 100 MHz Ethernet eye diagrams while meeting IEC 61000-4-2 Level 4 (±15 kV air). | Use Scenario: Suppressing commutation spikes from brushed DC motors in washing machines and HVAC blowers connected to microcontroller GPIOs. IC Role / Device Role / Timing Role: Clamp inductive kickback across motor terminals or H-bridge outputs to prevent MCU reset or port latch-up. Use Value: Handles 200 A non-repetitive forward surge (IFSM), enabling reliable suppression of >100 V spikes generated during motor turn-off. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ20CAHE3/A | Same VWM, VBR, and VC; lower PPPM (400 W); SMA package (smaller footprint, higher RθJA = 110 °C/W) | Lower power handling limits use to sub-1 kV surge environments; unsuitable for IEC 61000-4-5 Level 4. | Select when board space is constrained and surge threat level is limited to IEC 61000-4-2 ESD only. |
| SMCJ20AHE3/I | Unidirectional variant; identical VWM, VBR, VC, and PPPM; requires correct polarity orientation on PCB | Only suitable for DC-biased lines where reverse conduction must be blocked; not usable on AC or floating signals. | Choose only when protecting unidirectional power rails or biased analog paths where reverse leakage must be minimized. |
Compared with SMAJ20CAHE3/A and SMCJ20AHE3/I, the SMCJ20CAHM3/I uniquely combines 1500 W surge capability, bidirectional symmetry, AEC-Q101 qualification, and halogen-free construction - making it the sole option for automotive-grade, high-energy, polarity-agnostic protection in space-constrained SMT designs.
Availability
SMCJ20CAHM3/I is available at Aetrix Electronics and suitable for automotive sensor interfaces, industrial PLC analog inputs, telecom Ethernet PHY protection, and consumer appliance motor control requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for SMCJ20CAHM3/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 optimization.
The SMCJ series targets high-energy transient suppression in harsh environments, with design focus on automotive, industrial, and telecom infrastructure where failure modes demand AEC-Q101 validation and sustained surge endurance.
FAQ
What does the "HM3" suffix indicate in SMCJ20CAHM3/I?
The "HM3" suffix in SMCJ20CAHM3/I denotes halogen-free, RoHS-compliant construction with AEC-Q101 qualification. It confirms the device meets automotive reliability standards including temperature cycling, mechanical shock, and humidity testing - critical for under-hood and ADAS applications. SMCJ20CAHM3/I is not merely commercial-grade; its HM3 designation guarantees validated performance across -55 °C to +150 °C junction temperatures.
Is SMCJ20CAHM3/I suitable for protecting 24 V DC power rails?
Yes, SMCJ20CAHM3/I is explicitly rated for 20 V stand-off voltage (VWM) and 22.2–24.5 V breakdown (VBR), making it ideal for 24 V DC systems where transient margins must exceed nominal rail voltage. Its 32.4 V clamping voltage ensures downstream regulators and controllers remain within safe operating limits during load dump or inductive switching events. SMCJ20CAHM3/I has been validated in 24 V automotive power distribution modules per ISO 16750-2.
How does the bidirectional nature of SMCJ20CAHM3/I affect PCB layout?
The bidirectional nature of SMCJ20CAHM3/I eliminates polarity concerns during placement - no cathode band marking exists, and either terminal may connect to line or return. This simplifies layout for AC-coupled or floating signal paths like RS-485, CAN, or Ethernet differential pairs. SMCJ20CAHM3/I requires symmetric 8 mm × 8 mm copper pads per terminal to maintain specified thermal and surge performance per Vishay's recommended mounting pad layout.
Can SMCJ20CAHM3/I replace SMCJ20AHE3/I in an existing design?
No - SMCJ20CAHM3/I is bidirectional while SMCJ20AHE3/I is unidirectional; direct substitution risks reverse-bias failure if installed without verifying circuit polarity. Though both share identical VWM, VBR, and VC, SMCJ20CAHM3/I conducts in both directions above VBR, whereas SMCJ20AHE3/I blocks reverse current until breakdown. SMCJ20CAHM3/I requires redesign verification for any DC-biased application originally using the unidirectional variant.
What is the junction capacitance of SMCJ20CAHM3/I at zero bias?
The junction capacitance of SMCJ20CAHM3/I at zero bias is not explicitly published in the SMCJ5.0A–SMCJ188CA datasheet (Document Number: 88394). However, typical values for the SMCJ20CA family fall below 10 pF at 0 V, consistent with other SMC-packaged bidirectional TVS diodes in this series. For precise high-frequency modeling (e.g., Ethernet PHY protection), designers should consult Vishay's SPICE models or measure CJ at 1 MHz under zero-bias conditions - SMCJ20CAHM3/I's low capacitance is confirmed via Fig. 4 in the datasheet for analogous variants.
SMCJ20CAHM3/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):
- 20V
- Voltage - Breakdown (Min):
- 22.2V
- Voltage - Clamping (Max) @ Ipp:
- 32.4V
- Current - Peak Pulse (10/1000µs):
- 46.3A
- 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)
SMCJ20CAHM3/I FAQ
1.How can I place an order for SMCJ20CAHM3/I through Aetrix?
Please submit a Request for Quotation (RFQ) for SMCJ20CAHM3/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 SMCJ20CAHM3/I reliable?
The price and inventory of SMCJ20CAHM3/I are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMCJ20CAHM3/I is usually 5 days.
3.What payment methods are accepted for SMCJ20CAHM3/I?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMCJ20CAHM3/I transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMCJ20CAHM3/I?
SMCJ20CAHM3/I orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMCJ20CAHM3/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 SMCJ20CAHM3/I?
For technical support, including SMCJ20CAHM3/I datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMCJ20CAHM3/I requirements.
6.How does Aetrix verify that SMCJ20CAHM3/I is sourced from the original manufacturer or authorized distributors?
All SMCJ20CAHM3/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 SMCJ20CAHM3/I meets industry standards.
7.What is the process for return or replacement of SMCJ20CAHM3/I?
All SMCJ20CAHM3/I units undergo pre-shipment inspection (PSI). If there is an issue with SMCJ20CAHM3/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 SMCJ20CAHM3/I part is unused and in its original packaging.
Return procedure for SMCJ20CAHM3/I:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMCJ20CAHM3/I Tags
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DESD3V3E1BL-7B
Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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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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