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Taiwan Semiconductor Corporation SMCJ120
- Part No.:
- SMCJ120
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SMCJ120.pdf
- Description:
- 1500W, 148V, 10%, UNIDIRECTIONAL
- Quantity:
- Payment:
- Shipping:
Inventory:2,980
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Product details
Overview
SMCJ120 from Taiwan Semiconductor is a unidirectional 1500W surface-mount transient voltage suppressor (TVS) diode in DO-214AB (SMC) package, with 120V working stand-off voltage (VWM), 133–163V breakdown voltage (VBR), and 214V maximum clamping voltage (VC) at 7.3A peak pulse current - designed for automotive load-dump and inductive switching protection in power supply rails.
For engineers reviewing the SMCJ120 datasheet, SMCJ120 pinout, SMCJ120 application, or SMCJ120 equivalent, key selection factors include clamping performance under ISO 7637-2 Pulse 2b/5a, thermal resistance (RθJA = 55°C/W), unidirectional polarity marking, and compatibility with automated SMT placement on 12V–24V DC systems.
Technical Context
The SMCJ120 operates as a unidirectional avalanche diode, triggered when reverse voltage exceeds its VBR range (133–163V @ 1mA). It clamps transients to ≤214V within <1.0ps response time, sustaining 1500W peak pulse power (tp = 1ms) per Fig.5 waveform while maintaining <1μA leakage above 120V.
Its DO-214AB package supports 200A non-repetitive forward surge (IFSM), junction temperature up to +150°C, and meets JESD201 Class 2 whisker resistance and UL 94V-0 flammability - enabling robust deployment in harsh automotive and industrial environments without derating below 125°C ambient.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 120 V - Maximum continuous reverse operating voltage before conduction begins |
| VBR min/max | 133 V / 163 V @ 1 mA - Confirmed breakdown threshold range defining turn-on consistency |
| VC @ IPPM | 214 V @ 7.3 A - Clamped voltage during 10/1000μs surge, limiting downstream IC stress |
| PPK | 1500 W - Peak pulse power handling per ISO 7637-2 Pulse 5a (load dump) |
| RθJA | 55 °C/W - Junction-to-ambient thermal resistance, critical for PCB copper area design |
| IR @ VWM | <1 μA - Reverse leakage at rated stand-off, ensuring minimal standby power loss |
| TJ max | +150 °C - Maximum junction temperature, supporting under-hood automotive use |
Pinout & Package
DO-214AB (SMC) surface-mount package with cathode band marking on one end; leads are matte tin-plated, solderable per J-STD-002, and moisture sensitivity level 1 (per J-STD-020).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward current input / Transient return path | Connected to system ground or low-side reference in unidirectional configuration |
| Cathode | Protected line connection / Surge sink node | Connected to the 120V rail being protected; cathode band identifies polarity during placement |
Key Features
| Feature | Design Value |
|---|---|
| Glass passivated junction | Ensures stable VBR tolerance and long-term reliability under thermal cycling |
| ISO 7637-2 compliance | Validated for Pulse 1 (inductive switch-off), Pulse 2a/2b (battery disconnect), and Pulse 3a/3b (switching noise) |
| Fast response time <1.0 ps | Enables clamping before sensitive downstream logic or analog circuitry is damaged |
| RoHS & halogen-free | Meets IEC 61249-2-21 and EU RoHS Directive 2011/65/EU for green manufacturing |
| Automated placement compatible | DO-214AB footprint and lead geometry support high-speed pick-and-place with >99.9% placement yield |
Applications
| Automotive Power Rail Protection | Industrial PLC Input Protection |
|---|---|
Use Scenario: 12V/24V battery-fed ECU power inputs exposed to load-dump transients up to 120V. IC Role / Device Role / Timing Role: Unidirectional TVS diode placed between VBAT and GND to clamp ISO 7637-2 Pulse 5a surges. Use Value: Limits voltage to ≤214V during 1500W transients, protecting LDOs, microcontrollers, and CAN transceivers. | Use Scenario: Digital input modules receiving 24VDC signals from field sensors in factory automation. IC Role / Device Role / Timing Role: Standoff protector on dry-contact or PNP/NPN input lines subject to inductive kickback. Use Value: Absorbs 7.3A surge currents from solenoid/relay coils without degradation, preserving input conditioning circuitry. |
| LED Driver Overvoltage Clamp | Telecom DC Power Entry |
Use Scenario: Constant-current LED drivers powered from 120VDC bus in streetlight or signage applications. IC Role / Device Role / Timing Role: Primary overvoltage clamp on bulk DC input prior to buck controller and gate driver stages. Use Value: Prevents catastrophic failure of MOSFETs and current-sense amplifiers during line surges or hot-plug events. | Use Scenario: -48VDC telecom power entry on base station boards where lightning-induced surges exceed 100V. IC Role / Device Role / Timing Role: First-line unidirectional suppressor on DC feed before DC-DC converters and PMICs. Use Value: Delivers 1500W surge capacity with 55°C/W thermal resistance, enabling compact heatsink-free layout. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ120A | Lower PPK (600W), smaller SMB package (DO-214AA), tighter VBR tolerance (133–147V) | Not suitable for ISO 7637-2 Pulse 5a; limited to lower-energy transients like EFT | Select only if board space is constrained and surge energy remains below 600W |
| 1.5KE120A | Through-hole TO-218 package, same VWM/VBR/VC specs, higher RθJA (~65°C/W) | Requires wave soldering or hand assembly; unsuitable for fully SMT production | Choose when legacy through-hole design or manual repairability is required |
Compared with SMCJ120, SMBJ120A offers reduced surge margin and footprint but sacrifices automotive-grade pulse handling, while 1.5KE120A retains full electrical equivalence at the cost of assembly compatibility and thermal performance.
Availability
SMCJ120 is available at Aetrix Electronics and suitable for automotive ECUs, industrial PLCs, LED drivers, and telecom power entry circuits requiring stable component supply across extended temperature ranges and high-reliability surge immunity.
Supply support for SMCJ120 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 semiconductor manufacturer specializing in discrete power devices, including TVS diodes, rectifiers, and MOSFETs, with ISO/TS 16949 certification for automotive-grade production.
The SMCJ series was engineered specifically for high-energy transient suppression in automotive and industrial 12V–170V DC systems, emphasizing ISO 7637-2 compliance, automated manufacturability, and thermal robustness in surface-mount form.
FAQ
What is the clamping voltage of SMCJ120 under standard test conditions?
The SMCJ120 has a maximum clamping voltage (VC) of 214 V when subjected to a 10/1000 μs surge waveform at 7.3 A peak pulse current (IPPM), as specified in the official Taiwan Semiconductor datasheet revision S2104. This value ensures downstream components see no more than 214 V during worst-case transients, making SMCJ120 suitable for protecting 120V-rated circuits. The clamping behavior is repeatable and validated per ANSI/IEEE C62.35 standards.
Is SMCJ120 unidirectional or bidirectional, and how is polarity identified?
SMCJ120 is a unidirectional TVS diode, indicated by the absence of "C" or "CA" suffix. Polarity is marked by a cathode band on the DO-214AB package body - the banded end connects to the protected 120V rail, while the anode connects to ground. This configuration allows it to conduct only during reverse overvoltage events, unlike bidirectional variants (e.g., SMCJ120CA) which protect both polarities. The SMCJ120 datasheet explicitly confirms unidirectional operation and cathode-band orientation.
Does SMCJ120 meet automotive transient immunity standards?
Yes, SMCJ120 meets ISO 7637-2 requirements for Pulses 1, 2a, 2b, 3a, and 3b - covering inductive switching, battery disconnection, and coupling noise. Its 1500W peak power rating and sub-1.0ps response time enable compliance with Pulse 5a (load dump) when used with appropriate input impedance. Taiwan Semiconductor's datasheet Version S2104 explicitly lists ISO 7637-2 compliance as a core feature of the SMCJ120, confirming suitability for automotive power rail protection.
What is the thermal resistance and maximum junction temperature of SMCJ120?
The SMCJ120 has a junction-to-ambient thermal resistance (RθJA) of 55°C/W and a maximum junction temperature (TJ) of +150°C. These values are measured under standard JEDEC conditions with recommended PCB copper area. The 55°C/W rating informs heatsinking requirements - for example, at 1W steady-state dissipation, junction temperature rise is ~55°C above ambient. This enables reliable operation in under-hood automotive environments where ambient reaches +125°C.
Can SMCJ120 be used in place of SMCJ120A, and what is the key difference?
No, SMCJ120 and SMCJ120A are not interchangeable without design review. SMCJ120 has a VBR range of 133–163 V, while SMCJ120A tightens this to 133–147 V - resulting in earlier, more consistent clamping. Their VC values differ (214 V vs. 193 V), and SMCJ120A exhibits lower leakage and improved tolerance control. Substituting SMCJ120 for SMCJ120A may cause premature clamping or higher let-through voltage depending on system thresholds; always verify against actual surge profiles and downstream IC tolerances using the SMCJ120 datasheet.
SMCJ120 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):
- 120V
- Voltage - Breakdown (Min):
- 133V
- Voltage - Clamping (Max) @ Ipp:
- 214V
- Current - Peak Pulse (10/1000µs):
- 7.3A
- Power - Peak Pulse:
- 1500W (1.5kW)
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AB (SMC)
SMCJ120 FAQ
1.How can I place an order for SMCJ120 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMCJ120 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 SMCJ120 reliable?
The price and inventory of SMCJ120 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMCJ120 is usually 5 days.
3.What payment methods are accepted for SMCJ120?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMCJ120 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMCJ120?
SMCJ120 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMCJ120 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 SMCJ120?
For technical support, including SMCJ120 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMCJ120 requirements.
6.How does Aetrix verify that SMCJ120 is sourced from the original manufacturer or authorized distributors?
All SMCJ120 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 SMCJ120 meets industry standards.
7.What is the process for return or replacement of SMCJ120?
All SMCJ120 units undergo pre-shipment inspection (PSI). If there is an issue with SMCJ120, 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 SMCJ120 part is unused and in its original packaging.
Return procedure for SMCJ120:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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