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STMicroelectronics SMCJ40A-TR
- Part No.:
- SMCJ40A-TR
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SMCJ40A-TR.pdf
- Description:
- TVS DIODE 40VWM 84VC SMC
- Quantity:
- Payment:
- Shipping:
Inventory:13,195
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Product details
Overview
SMCJ40A-TR from STMicroelectronics is a unidirectional 1500 W transient voltage suppression (TVS) diode in SMC package, designed for primary-level surge protection of DC power rails and signal lines. It features a 40 V standoff voltage (VRM), 44.4–46.7 V breakdown voltage at 1 mA, 64.5 V clamping voltage at 24 A (10/1000 µs), and operates up to 150 °C junction temperature - deployed in industrial power supplies and automotive body control modules.
For engineers reviewing the SMCJ40A-TR datasheet, SMCJ40A-TR pinout, SMCJ40A-TR application, or SMCJ40A-TR equivalent, key selection criteria include clamping voltage under 24 A surge, low leakage (<0.2 µA at 25 °C), thermal derating above 25 °C, and compatibility with IPC7531-compliant SMC footprint for high-reliability PCB layouts.
Technical Context
This TVS diode uses planar silicon junction technology to achieve low dynamic resistance (0.644 Ω) and stable clamping performance across temperature. Its unidirectional configuration enables asymmetric surge suppression on positive-polarity DC lines without reverse conduction during normal operation.
The device meets IEC 61000-4-2 level 4 ESD immunity (30 kV air/contact discharge) and IEC 61000-4-4 level 4 surge immunity (4 kV), with peak pulse power rated at 1500 W (10/1000 µs) and up to 10 kW (8/20 µs) - supporting robust front-end protection in SMPS and motor drive interfaces.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Standoff Voltage (VRM) | 40 V - maximum continuous DC operating voltage before leakage exceeds 0.2 µA |
| Breakdown Voltage (VBR) | 44.4–46.7 V at 1 mA - precise threshold for initiating avalanche conduction during overvoltage events |
| Clamping Voltage (VCL) | 64.5 V at 24 A (10/1000 µs) - limits downstream voltage stress during standardized surge transients |
| Peak Pulse Power (PPP) | 1500 W (10/1000 µs) - defines maximum single-event energy absorption capability at 25 °C ambient |
| Leakage Current (IRM) | ≤0.2 µA at VRM and 25 °C - ensures minimal standby power loss and signal integrity in high-impedance circuits |
| Junction Temperature Range | −55 to +150 °C - supports operation in under-hood automotive and industrial environments without derating |
| Package | SMC (DO-214AB) - JEDEC-registered surface-mount outline with 7.75–8.15 mm body length and 5.55–6.25 mm width |
Pinout & Package
SMCJ40A-TR is housed in an SMC (DO-214AB) plastic package with two terminals: Cathode (marked end) and Anode. The package complies with IPC7531 footprint standards and JEDEC MO-136AC outline, optimized for thermal dissipation on FR4 PCBs with ≥3.14 cm² copper area per lead.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (marked end) | Surge current sink node | Connected to protected line; conducts avalanche current to ground during overvoltage |
| Anode | Reference / return path | Typically tied to system ground or lower-potential rail; completes conduction path during transient |
Key Features
| Feature | Design Value |
|---|---|
| Low clamping ratio | VCL/VBR = 64.5 V / 44.4 V ≈ 1.45 - minimizes voltage overshoot relative to breakdown threshold |
| High-temperature stability | Rated for full 1500 W pulse power up to 125 °C junction temperature - enables compact layout without forced cooling |
| ESD robustness | Exceeds IEC 61000-4-2 level 4 (30 kV contact/air) - protects against human-body-model and machine-model discharges |
| Lead finish | Matte tin plating - ensures solderability per J-STD-002 and whisker resistance per JESD201 class 2 |
| UL94 V0 compliance | Epoxy housing self-extinguishes within 10 s after flame removal - satisfies safety requirements for enclosed power systems |
Applications
| Industrial Power Supply Protection | Automotive Body Control Module |
|---|---|
|
Use Scenario: Input stage of 48 V DC-DC converter subjected to load-dump transients and ISO 7637-2 pulses. IC Role / Device Role / Timing Role: Primary surge clamp on main input rail, absorbing >100 J energy in <100 ms events. Use Value: Limits rail voltage to ≤64.5 V during 24 A surges, preventing damage to upstream MOSFETs and controller ICs. |
Use Scenario: LIN bus interface circuit exposed to battery voltage spikes and ESD in door module electronics. IC Role / Device Role / Timing Role: Unidirectional TVS placed between LIN line and ground to suppress fast transients without disrupting communication. Use Value: Clamps 8/20 µs surges to <84 V at 119 A, preserving signal integrity while meeting ISO 10605 ESD requirements. |
| Telecom DC Feeder Protection | Renewable Energy Inverter DC Link |
|
Use Scenario: 48 V telecom power feed line vulnerable to lightning-induced surges on outdoor cabling. IC Role / Device Role / Timing Role: First-line protection device mounted at equipment entry point, coordinated with upstream GDTs. Use Value: Withstands repeated 10/1000 µs surges up to 1500 W, enabling >100,000 surge cycles per MIL-STD-750 method 2026. |
Use Scenario: DC link between PV array and MPPT controller in solar inverters, subject to switching transients and grid faults. IC Role / Device Role / Timing Role: Bidirectional clamping not applicable; unidirectional SMCJ40A-TR used on grounded-rail side for asymmetrical fault protection. Use Value: Maintains <0.2 µA leakage at 40 V, avoiding parasitic drain in high-impedance MPPT sensing circuits. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar unidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ40A-TR | Lower PPP rating: 600 W (10/1000 µs); same VBR and VCL; SMB package (smaller footprint, higher thermal resistance) | Suitable only for lower-energy surges; requires larger copper area to match SMCJ40A-TR's thermal performance | Select when board space is constrained and surge threat level is ≤600 W. |
| 1.5KE40A | Through-hole DO-201 package; identical electrical specs but higher thermal mass; lead time and RoHS status differ | Used where manual assembly or legacy through-hole design is required; not suitable for automated SMT lines | Select for prototyping or repair scenarios requiring hand-soldering compatibility. |
Compared with SMBJ40A-TR and 1.5KE40A, SMCJ40A-TR delivers 2.5× higher surge power handling in an SMT-optimized package, enabling smaller PCB area than DO-201 while maintaining superior thermal derating above 25 °C - critical for sealed industrial enclosures.
Availability
SMCJ40A-TR is available at Aetrix Electronics and suitable for industrial power supply protection, automotive body control modules, telecom DC feeder protection, and renewable energy inverter DC link applications requiring stable component supply and long-term lifecycle support.
Supply support for SMCJ40A-TR 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
STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, specializing in power management, analog, MEMS, and microcontroller technologies for industrial, automotive, and consumer markets.
SMCJxxA/CA belongs to ST's high-power TVS diode product line, engineered specifically for robust transient suppression in harsh-environment power electronics where reliability, thermal resilience, and IEC/ISO compliance are mandatory.
FAQ
What is the maximum clamping voltage of SMCJ40A-TR under a 10/1000 µs surge?
The maximum clamping voltage (VCL) is 64.5 V at 24 A for a 10/1000 µs waveform, measured at 25 °C ambient. This value increases with junction temperature at a coefficient of 10.1 × 10⁻⁴/°C, reaching ~70.2 V at 125 °C junction temperature per the datasheet's αT correction formula.
Is SMCJ40A-TR bidirectional or unidirectional?
SMCJ40A-TR is unidirectional - it conducts only during positive overvoltage events on the cathode terminal relative to anode. Its counterpart SMCJ40CA is bidirectional. The "A" suffix explicitly denotes unidirectional polarity, confirmed by marking "FUU" and electrical test data showing no reverse conduction beyond leakage.
Does SMCJ40A-TR meet automotive qualification standards?
While not AEC-Q200 qualified, SMCJ40A-TR meets key automotive-relevant standards: IEC 61000-4-2 (30 kV ESD), IEC 61000-4-4 (4 kV surge), and operates from −55 to +150 °C. It is widely deployed in non-safety-critical automotive subsystems such as body control modules and infotainment power rails.
What is the recommended PCB footprint for SMCJ40A-TR?
The recommended footprint follows IPC7531 and JEDEC MO-136AC: pad length 5.11 mm, pad width 3.14 mm, center-to-center spacing 8.19 mm, with ≥3.14 cm² copper area per lead. This layout achieves Rth(j-a) ≈ 40 °C/W per Figure 12, enabling full 1500 W pulse power at 25 °C ambient.
SMCJ40A-TR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- DO-214AB, SMC
- Series:
- SMCJ, TRANSIL™
- 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:
- 84V
- Current - Peak Pulse (10/1000µs):
- 119A (8/20µs)
- 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:
- SMC
SMCJ40A-TR FAQ
1.How can I place an order for SMCJ40A-TR through Aetrix?
Please submit a Request for Quotation (RFQ) for SMCJ40A-TR 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 SMCJ40A-TR reliable?
The price and inventory of SMCJ40A-TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMCJ40A-TR is usually 5 days.
3.What payment methods are accepted for SMCJ40A-TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMCJ40A-TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMCJ40A-TR?
SMCJ40A-TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMCJ40A-TR 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 SMCJ40A-TR?
For technical support, including SMCJ40A-TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMCJ40A-TR requirements.
6.How does Aetrix verify that SMCJ40A-TR is sourced from the original manufacturer or authorized distributors?
All SMCJ40A-TR 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 SMCJ40A-TR meets industry standards.
7.What is the process for return or replacement of SMCJ40A-TR?
All SMCJ40A-TR units undergo pre-shipment inspection (PSI). If there is an issue with SMCJ40A-TR, 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 SMCJ40A-TR part is unused and in its original packaging.
Return procedure for SMCJ40A-TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMCJ40A-TR Tags
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