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Taiwan Semiconductor Corporation SMCJ12A
- Part No.:
- SMCJ12A
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SMCJ12A.pdf
- Description:
- TVS DIODE 12VWM 19.9VC SMC
- Quantity:
- Payment:
- Shipping:
Inventory:1,230
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Product details
Overview
SMCJ12A from Taiwan Semiconductor is a unidirectional 1500W surface-mount transient voltage suppressor (TVS) diode with 12V working stand-off voltage, 13.3–14.7V breakdown range at 1mA test current, and 19.9V maximum clamping voltage at 79A peak pulse current. It protects automotive power rails and industrial I/O interfaces against ISO 7637-2 Pulse 1/2a/2b/3a/3b transients.
For engineers reviewing the SMCJ12A datasheet, SMCJ12A pinout, SMCJ12A application, or SMCJ12A equivalent, key selection criteria include clamping voltage margin relative to protected IC VDD, junction temperature derating above 25°C, unidirectional polarity marking, and DO-214AB (SMC) footprint compatibility with automated placement.
Technical Context
The SMCJ12A uses a glass-passivated silicon junction optimized for sub-1ps response to fast-rising ESD and load-dump transients. Its unidirectional configuration provides low forward voltage (3.5V @ 100A) while maintaining <1μA reverse leakage at 12V, enabling direct placement across DC supply lines without standby power penalty.
Thermal performance is defined by RθJA = 55°C/W and RθJC = 10°C/W, supporting operation up to +150°C junction temperature. The device meets JESD201 Class 2 whisker resistance and UL 94V-0 flammability requirements in its DO-214AB molded package.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 12 V - Maximum continuous reverse operating voltage before clamping begins |
| VBR min/max | 13.3 V / 14.7 V @ 1 mA - Confirmed breakdown threshold range for design margining |
| VC @ IPPM | 19.9 V @ 79 A - Clamped voltage during 10/1000μs surge, defining protection window for downstream ICs |
| PPK | 1500 W - Peak pulse power handling per single 1ms transient, per Fig.5 waveform |
| IR @ VWM | <1 μA - Reverse leakage ensuring negligible standby current in always-on systems |
| TJ max | +150 °C - Maximum junction temperature enabling under-hood automotive use |
| Package | DO-214AB (SMC) - Standardized 2-pin surface-mount outline with cathode band marking |
Pinout & Package
DO-214AB (SMC) package: 2-terminal surface-mount device with cathode band indicating pin 1 (cathode), pin 2 (anode). Matte tin-plated leads meet J-STD-002 solderability; polarity marking enables correct orientation during automated placement.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (marked end) | Reverse-biased terminal during normal operation | Connected to protected line (e.g., 12V rail); conducts only during overvoltage events |
| Anode | Reference/ground return path | Connected to system ground or low-impedance return plane; defines clamping reference point |
Key Features
| Feature | Design Value |
|---|---|
| ISO 7637-2 compliance | Validated for Pulse 1 (inductive load dump), Pulse 2a/2b (switching transients), and Pulse 3a/3b (capacitive coupling), enabling drop-in use in automotive ECUs |
| Sub-1ps response time | Clamps within <1.0 ps from 0 V to VBR min, intercepting ESD and fast transients before sensitive logic is damaged |
| Moisture sensitivity level 1 | No floor life limitation or bake requirement prior to reflow, simplifying SMT line integration |
| Halogen-free construction | Complies with IEC 61249-2-21, meeting RoHS and environmental compliance mandates for global OEMs |
| UL 94V-0 molding compound | Self-extinguishing encapsulation prevents flame propagation in high-energy fault conditions |
Applications
| Automotive Power Rail Protection | Industrial PLC Digital I/O Protection |
|---|---|
Use Scenario: 12V battery-supplied engine control unit exposed to load-dump transients up to 35V per ISO 7637-2 Pulse 5a. IC Role / Device Role / Timing Role: Unidirectional TVS placed between battery input and DC-DC converter input to clamp surges before regulation stage. Use Value: 19.9V clamping ensures downstream 24V-rated input capacitors and LDOs remain within safe operating area during 1500W transients. | Use Scenario: 24V digital input module receiving signals from field sensors in factory automation environments. IC Role / Device Role / Timing Role: SMCJ12A deployed across each input channel to suppress EFT bursts (IEC 61000-4-4) and contact bounce-induced spikes. Use Value: Sub-1ps response and <1μA leakage preserve signal integrity and minimize false triggering in high-impedance sensing circuits. |
| LED Driver Overvoltage Clamp | Telecom Power Interface Protection |
Use Scenario: Constant-current LED driver board powered from 12V supply in outdoor signage, subject to lightning-induced surges. IC Role / Device Role / Timing Role: TVS mounted at DC input connector to absorb induced transients before reaching buck controller and MOSFET gate drivers. Use Value: 1500W peak power rating handles multi-kV/m field-coupled energy without degradation, extending board lifetime in harsh environments. | Use Scenario: 12V auxiliary power interface on telecom base station backplane exposed to hot-swap and cable discharge events. IC Role / Device Role / Timing Role: SMCJ12A used as primary front-end clamp on 12V bias rail feeding FPGA I/O banks and SerDes power supplies. Use Value: DO-214AB footprint allows dense layout near connectors; 55°C/W thermal resistance supports operation in sealed enclosures up to +85°C ambient. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ12A | 600W peak power rating, same VWM/VBR/VC specs, SMB package (smaller footprint, higher thermal resistance) | Limited to lower-energy transients; unsuitable for ISO 7637-2 Pulse 5a load-dump | Select SMCJ12A when 1500W surge immunity is required; SMBJ12A fits space-constrained designs with lower threat profiles. |
| SMCJ12CA | Bidirectional variant with identical VWM, VBR, VC, and PPK, but symmetrical clamping in both polarities | Required for AC-coupled or floating signal lines where reverse polarity transients occur | Choose SMCJ12A for DC supply rail protection; SMCJ12CA only if bidirectional clamping is mandated by circuit topology. |
Compared with SMBJ12A and SMCJ12CA, the SMCJ12A delivers optimal balance of 1500W surge capacity, DO-214AB mechanical robustness, and unidirectional efficiency for 12V DC power rail protection-without requiring PCB redesign or thermal derating.
Availability
SMCJ12A is available at Aetrix Electronics and suitable for automotive ECU design, industrial PLC I/O modules, LED driver boards, and telecom power interface protection requiring stable component supply and full ISO 7637-2 compliance.
Supply support for SMCJ12A 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
Taiwan Semiconductor Corporation (TSC) is a vertically integrated analog and discrete semiconductor manufacturer headquartered in Hsinchu, Taiwan, specializing in TVS diodes, rectifiers, and power management devices since 1979.
The SMCJ series was engineered specifically for high-energy transient suppression in automotive and industrial environments, emphasizing rugged packaging, ISO-standard validation, and consistent parametric performance across temperature and lot variations.
FAQ
What is the clamping voltage of the SMCJ12A under a 10/1000μs surge?
The SMCJ12A has a maximum clamping voltage (VC) of 19.9 V at 79 A peak pulse current, measured using the standardized 10/1000μs double-exponential waveform per IEC 61000-4-5. This value defines the upper voltage limit imposed on protected circuitry during worst-case transient events and is confirmed in the Electrical Specifications table on page 2 of the Taiwan Semiconductor S2104 datasheet for SMCJ12A.
Is the SMCJ12A unidirectional or bidirectional?
The SMCJ12A is a unidirectional transient voltage suppressor, indicated by the absence of "C" or "CA" suffix and confirmed by its forward voltage specification (3.5 V @ 100 A) and cathode-band polarity marking. It conducts only during reverse overvoltage events and blocks forward current, making it suitable for DC supply rail protection where polarity is fixed. Bidirectional variants carry "CA" suffix (e.g., SMCJ12CA).
Does the SMCJ12A meet automotive transient standards?
Yes, the SMCJ12A meets ISO 7637-2 requirements for Pulse 1 (inductive switch-off), Pulse 2a/2b (battery interruption and coupling), and Pulse 3a/3b (capacitive discharge), as explicitly stated in the FEATURES section of the Taiwan Semiconductor S2104 datasheet. Its 1500W peak power rating and 19.9V clamping enable compliance with these waveforms without external circuitry.
What is the thermal resistance of the SMCJ12A in its DO-214AB package?
The SMCJ12A has a junction-to-ambient thermal resistance (RθJA) of 55°C/W and a junction-to-case thermal resistance (RθJC) of 10°C/W, as specified in the THERMAL PERFORMANCE section of the S2104 datasheet. These values assume standard JEDEC PCB mounting conditions and define allowable power dissipation derating above 25°C ambient, critical for under-hood automotive deployment.
How does the SMCJ12A differ from the SMCJ12 part number?
The SMCJ12A offers tighter breakdown voltage tolerance (13.3–14.7 V) compared to SMCJ12 (13.3–16.3 V), resulting in more predictable clamping behavior and reduced design margin uncertainty. Both share identical package, power rating, and application scope, but SMCJ12A's narrower VBR range improves consistency in mass production and reduces risk of over-clamping in sensitive 12V systems.
SMCJ12A Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Taiwan Semiconductor Corporation
- Package/Case:
- DO-214AB, SMC
- Series:
- SMCJ
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 12V
- Voltage - Breakdown (Min):
- 13.3V
- Voltage - Clamping (Max) @ Ipp:
- 19.9V
- Current - Peak Pulse (10/1000µs):
- 75.4A
- Power - Peak Pulse:
- 1500W (1.5kW)
- Power Line Protection:
- Yes
- Applications:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AB (SMCJ)
SMCJ12A FAQ
1.How can I place an order for SMCJ12A through Aetrix?
Please submit a Request for Quotation (RFQ) for SMCJ12A 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 SMCJ12A reliable?
The price and inventory of SMCJ12A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMCJ12A is usually 5 days.
3.What payment methods are accepted for SMCJ12A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMCJ12A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMCJ12A?
SMCJ12A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMCJ12A 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 SMCJ12A?
For technical support, including SMCJ12A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMCJ12A requirements.
6.How does Aetrix verify that SMCJ12A is sourced from the original manufacturer or authorized distributors?
All SMCJ12A 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 SMCJ12A meets industry standards.
7.What is the process for return or replacement of SMCJ12A?
All SMCJ12A units undergo pre-shipment inspection (PSI). If there is an issue with SMCJ12A, 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 SMCJ12A part is unused and in its original packaging.
Return procedure for SMCJ12A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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