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Taiwan Semiconductor Corporation SMCJ40
- Part No.:
- SMCJ40
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SMCJ40.pdf
- Description:
- 1500W, 49.4V, 10%, UNIDIRECTIONA
- Quantity:
- Payment:
- Shipping:
Inventory:3,000
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Product details
Overview
SMCJ40 from Taiwan Semiconductor is a unidirectional 1500W surface-mount transient voltage suppressor (TVS) diode in DO-214AB (SMC) package, with 40V working stand-off voltage (VWM), 44.4–54.3V breakdown voltage (VBR), and 71.4V maximum clamping voltage (VC) at 22A peak pulse current - designed for automotive load-dump and inductive switching surge protection in power supply rails.
For engineers reviewing the SMCJ40 datasheet, SMCJ40 pinout, SMCJ40 application, or SMCJ40 equivalent, key selection criteria include clamping performance under ISO 7637-2 Pulse 1/2a/2b/3a/3b, junction temperature derating above 25°C, moisture sensitivity level (MSL 1), and compatibility with automated SMT placement on high-reliability industrial and automotive PCBs.
Technical Context
The SMCJ40 operates as a unidirectional avalanche diode, triggering when reverse voltage exceeds its VBR range (44.4–54.3V @ 1mA), clamping transients to ≤71.4V at 22A (10/1000μs waveform). Its glass-passivated junction ensures stable breakdown and low leakage (<1μA @ 40V).
Thermal design relies on RθJA = 55°C/W and RθJC = 10°C/W, supporting continuous operation up to TJ = 150°C. It meets JESD201 Class 2 whisker resistance and UL 94V-0 flammability requirements for the molding compound.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 40 V - Maximum DC or RMS voltage the device blocks continuously without conduction |
| VBR min/max | 44.4 V / 54.3 V @ 1 mA - Ensures reliable turn-on margin above VWM for robust surge detection |
| VC @ IPPM | 71.4 V @ 22 A (10/1000 μs) - Clamping voltage limiting downstream IC stress during worst-case transients |
| PPK | 1500 W - Peak pulse power handling capability per single non-repetitive surge event |
| IR @ VWM | <1 μA - Negligible leakage current preserving system standby power integrity |
| TJ max | +150 °C - Maximum junction temperature enabling operation in under-hood automotive environments |
| Package | DO-214AB (SMC) - Standardized surface-mount outline compatible with IPC-7351B land patterns |
Pinout & Package
DO-214AB (SMC) package: molded plastic case with matte tin-plated leads; cathode indicated by band marking; polarity-critical for unidirectional operation; MSL Level 1 per J-STD-020; weight ≈ 0.210 g.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward current entry / Reverse surge return path | Connected to protected circuit ground or low-side reference; must be routed with low-inductance trace |
| Cathode | Reverse voltage sensing / Clamping output node | Connected to line being protected (e.g., 40V rail); cathode band identifies this terminal physically |
Key Features
| Feature | Design Value |
|---|---|
| Glass-passivated junction | Stable VBR tolerance and long-term reliability under thermal cycling and humidity exposure |
| ISO 7637-2 compliance | Validated immunity to automotive electrical transients including Pulse 1 (inductive load dump), Pulse 2a/2b, and Pulse 3a/3b |
| Fast response time | <1.0 ps rise from 0 V to VBR - Enables suppression before sensitive downstream logic or analog circuits are damaged |
| Halogen-free construction | Complies with IEC 61249-2-21 - Supports RoHS-compliant and environmentally regulated end-product certifications |
| Automated placement compatibility | DO-214AB geometry and lead finish meet J-STD-002 solderability standards for high-yield SMT assembly |
Applications
| Automotive Power Rail Protection | Industrial PLC Input Protection |
|---|---|
Use Scenario: Protecting 40V battery-fed control modules against load-dump spikes up to 120V during alternator regulation failure. IC Role / Device Role / Timing Role: Unidirectional TVS clamp placed between power rail and chassis ground, absorbing energy within 10/1000μs waveform envelope. Use Value: Limits rail voltage to ≤71.4V during 22A surge, preventing damage to 48V-rated DC-DC controllers and CAN transceivers. | Use Scenario: Safeguarding 24–48V digital input channels of programmable logic controllers from field-wiring ESD and inductive kickback. IC Role / Device Role / Timing Role: Front-end transient suppressor on isolated input terminals, shunting surges before optocoupler or Schmitt-trigger input stages. Use Value: Withstands ≥1000 surges at rated PPK while maintaining <1μA leakage - preserves signal integrity and reduces false triggering. |
| LED Driver Overvoltage Clamp | Telecom Power Interface Protection |
Use Scenario: Clamping overvoltage events on constant-current LED driver outputs subjected to cable disconnect transients. IC Role / Device Role / Timing Role: Parallel-connected TVS across output terminals, activated only during fault conditions exceeding 40V. Use Value: 71.4V clamping voltage ensures connected LED strings remain below absolute maximum ratings even during 1500W surge events. | Use Scenario: Protecting 48V telecom power interface cards from lightning-induced surges entering via backplane or external ports. IC Role / Device Role / Timing Role: Primary-level surge arrestor on -48V DC feed lines, coordinated with secondary MOVs and filtering networks. Use Value: 1500W peak power rating enables coordination with upstream protection stages without thermal runaway or premature failure. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| Littelfuse SMAJ40A | Same DO-214AC (SMA) package; lower PPK (400W); VBR 44.4–49.1V; VC = 64.5V @ 24A | Lower power rating limits use to sub-automotive or low-energy industrial transients | Select SMAJ40A only where board space constraints favor SMA over SMC and surge energy is ≤400W |
| ON Semiconductor 1.5SMC40A | Identical DO-214AB (SMC) package; same PPK (1500W); VBR 44.4–54.3V; VC = 71.4V @ 22A - matches SMCJ40 parametrically | No functional deviation; validated for identical ISO 7637-2 test pulses | 1.5SMC40A is a direct form-fit-function alternative with equivalent clamping and thermal performance |
Compared with SMAJ40A and 1.5SMC40A, the SMCJ40 offers identical clamping behavior and automotive-grade surge capacity in the larger SMC package - making it preferable for high-energy applications where thermal mass and PCB layout allow, while 1.5SMC40A serves as a drop-in replacement where second-source assurance is required.
Availability
SMCJ40 is available at Aetrix Electronics and suitable for automotive electronics, industrial PLCs, LED lighting systems, and telecom power interfaces requiring stable component supply with full traceability and lifecycle management.
Supply support for SMCJ40 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, TVS diodes, rectifiers, and MOSFETs for industrial and automotive markets.
The SMCJ series is part of TSC's high-power transient suppression product line, engineered specifically for ISO 7637-2-compliant surge protection in harsh-environment 12V/24V/48V systems.
FAQ
What is the clamping voltage of the SMCJ40 under standard 10/1000μs surge conditions?
The SMCJ40 has a maximum clamping voltage (VC) of 71.4 V when subjected to a 22 A peak pulse current with a 10/1000 μs waveform. This value is measured per ANSI/IEEE C62.35 and defines the upper voltage limit imposed on the protected circuit during transient events - critical for ensuring downstream components like DC-DC converters or microcontrollers remain within their absolute maximum ratings. The SMCJ40 maintains this clamping performance consistently across its specified operating temperature range.
Is the SMCJ40 suitable for bidirectional transient suppression?
No, the SMCJ40 is a unidirectional TVS diode intended for DC rail protection with defined polarity. For bidirectional applications, Taiwan Semiconductor specifies the SMCJ40CA variant (with "CA" suffix), which features symmetrical breakdown in both directions. Using the SMCJ40 in reverse-biased AC or bipolar signal paths risks permanent failure due to forward conduction beyond its 3.5 V VF rating. Always verify part suffix and consult the official SMCJ40 datasheet before substituting in bidirectional designs.
What is the maximum steady-state power dissipation (PD) of the SMCJ40 at room temperature?
The SMCJ40 has a steady-state power dissipation (PD) rating of 5 W at TA = 25°C. This value reflects continuous DC power handling capability - not surge energy - and is limited by thermal resistance (RθJA = 55°C/W). In practice, the SMCJ40 is not operated continuously near PD due to its role as a transient protector; sustained power dissipation should remain well below 5 W to avoid junction overheating, especially at elevated ambient temperatures where derating applies per Figure 2 in the datasheet.
Does the SMCJ40 meet automotive qualification standards such as AEC-Q101?
The SMCJ40 is designed to meet ISO 7637-2 Pulse 1/2a/2b/3a/3b for automotive electrical transient immunity but is not explicitly qualified to AEC-Q101 in the provided documentation. Taiwan Semiconductor's AEC-Q101-qualified equivalents include the SMAJ-AEC series in SMA package. For mission-critical automotive applications requiring formal qualification evidence, engineers should request AEC-Q101 test reports directly from TSC or select an AEC-Q101-certified alternative. The SMCJ40 remains widely used in non-safety-critical automotive subsystems where ISO 7637-2 compliance is the primary requirement.
How does the SMCJ40 compare to the SMCJ40A variant?
The SMCJ40A differs from the SMCJ40 primarily in tighter VBR tolerance: SMCJ40A has VBR = 44.4–49.1 V (vs. 44.4–54.3 V for SMCJ40), resulting in lower maximum clamping voltage (64.5 V vs. 71.4 V) at the same 24 A test current. Both share identical package (DO-214AB), PPK (1500 W), and thermal specs. The SMCJ40A provides more predictable turn-on behavior in precision-clamp applications, while the standard SMCJ40 offers broader VBR coverage for cost-sensitive or less stringent designs. Select SMCJ40A when clamping consistency is prioritized over margin to VWM.
SMCJ40 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):
- 40V
- Voltage - Breakdown (Min):
- 44.4V
- Voltage - Clamping (Max) @ Ipp:
- 71.4V
- Current - Peak Pulse (10/1000µs):
- 22A
- 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)
SMCJ40 FAQ
1.How can I place an order for SMCJ40 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMCJ40 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 SMCJ40 reliable?
The price and inventory of SMCJ40 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMCJ40 is usually 5 days.
3.What payment methods are accepted for SMCJ40?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMCJ40 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMCJ40?
SMCJ40 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMCJ40 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 SMCJ40?
For technical support, including SMCJ40 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMCJ40 requirements.
6.How does Aetrix verify that SMCJ40 is sourced from the original manufacturer or authorized distributors?
All SMCJ40 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 SMCJ40 meets industry standards.
7.What is the process for return or replacement of SMCJ40?
All SMCJ40 units undergo pre-shipment inspection (PSI). If there is an issue with SMCJ40, 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 SMCJ40 part is unused and in its original packaging.
Return procedure for SMCJ40:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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