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STMicroelectronics SMCJ12A-TR
- Part No.:
- SMCJ12A-TR
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SMCJ12A-TR.pdf
- Description:
- TVS DIODE 12VWM 25.3VC SMC
- Quantity:
- Payment:
- Shipping:
Inventory:877
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Product details
Overview
SMCJ12A-TR from STMicroelectronics is a unidirectional 1500 W transient voltage suppression (TVS) diode in SMC package, designed for primary-level ESD and surge protection on DC power rails and signal lines. It features a 12 V standoff voltage (VRM), 13.3 V minimum breakdown voltage (VBR), 19.9 V clamping voltage (VCL) at 79 A peak pulse current (IPP), and operates up to 150 °C junction temperature - deployed in industrial power supplies and automotive body control modules.
For engineers reviewing the SMCJ12A-TR datasheet, SMCJ12A-TR pinout, SMCJ12A-TR application, or SMCJ12A-TR equivalent, key selection criteria include clamping performance under 10/1000 µs surges, low leakage (<0.2 µA at 25 °C), thermal stability at Tj = 150 °C, and compliance with IEC 61000-4-2 (±30 kV contact/air) and IEC 61000-4-4 Level 4 (4 kV).
Technical Context
This planar-junction TVS diode uses silicon avalanche technology to clamp transient overvoltages via controlled reverse-biased breakdown. Its unidirectional configuration provides asymmetric protection - forward conduction only during positive transients on anode-referenced lines - with dynamic resistance of 0.066 Ω at 25 °C enabling fast response to 8/20 µs surges.
Thermal derating is defined by αT = 10⁻⁴ /°C, allowing precise VBR and VCL adjustment across –55 °C to +150 °C operating range. The device sustains 1250 W peak pulse power at maximum junction temperature (Tj = 150 °C), confirming suitability for high-reliability, thermally constrained environments like enclosed motor drives and LED drivers.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Standoff Voltage (VRM) | 12 V - Maximum continuous reverse working voltage before clamping initiates; sets minimum system operating margin. |
| Breakdown Voltage (VBR) | 13.3–14.0 V @ 1 mA - Confirmed avalanche onset threshold; ensures predictable turn-on during overvoltage events. |
| Clamping Voltage (VCL) | 19.9 V @ 79 A (10/1000 µs) - Peak voltage seen by protected circuit during worst-case surge; defines downstream component stress. |
| Peak Pulse Power (PPP) | 1500 W @ 10/1000 µs - Sustained energy-handling capability for standard lightning/surge waveforms per IEC 61000-4-5. |
| Leakage Current (IRM) | 0.2 µA @ 12 V, 25 °C - Ultra-low reverse leakage preserves battery life and avoids false triggering in low-power sensor nodes. |
| Junction Temperature Range | –55 °C to +150 °C - Enables operation in under-hood automotive, industrial PLCs, and outdoor telecom equipment without derating. |
| ESD Robustness | ±30 kV contact/air discharge (IEC 61000-4-2) - Exceeds Level 4 immunity; protects USB, CAN, and RS-485 interfaces against human-body-model discharges. |
Pinout & Package
SMCJ12A-TR is housed in an SMC (DO-214AB) surface-mount package with two terminals: Cathode (K) and Anode (A). The package measures 5.55–6.25 mm (L) × 7.75–8.15 mm (W) × 2.45 mm (H), compliant with IPC7531 footprint and JEDEC MO-136 standards.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (A) | Transient return path | Connected to ground or low-impedance reference; completes clamping loop during positive surges. |
| Cathode (K) | Protected line connection | Connected to input rail or signal line; voltage rise above VRM triggers avalanche conduction to anode. |
Key Features
| Feature | Design Value |
|---|---|
| High surge capability | 1500 W (10/1000 µs) and up to 10 kW (8/20 µs) - Supports both lightning-induced and switching-spike protection in AC/DC front-ends. |
| Low dynamic resistance | 0.066 Ω at 25 °C - Minimizes VCL rise under high-current transients, preserving voltage margin for downstream ICs. |
| Extended thermal rating | 150 °C max junction temperature - Eliminates need for thermal derating in sealed enclosures or high-ambient environments. |
| UL94 V0 epoxy housing | Flame-retardant encapsulation - Meets safety requirements for industrial and medical power systems. |
| Matte tin lead finish | RoHS-compliant, solderable termination - Ensures reliable reflow attachment per J-STD-020 MSL Level 1. |
Applications
| Industrial Power Supply Input Protection | Automotive Body Control Module (BCM) |
|---|---|
|
Use Scenario: 24 V DC input rail exposed to load-dump transients and ISO 7637-2 pulses in factory automation controllers. IC Role / Device Role / Timing Role: Primary clamping element placed upstream of DC-DC converters and microcontrollers to limit voltage excursions below 20 V. Use Value: Clamps 10/1000 µs surges to ≤19.9 V at 79 A, preventing latch-up or permanent damage to 3.3 V/5 V logic and gate drivers. |
Use Scenario: LIN bus and 12 V power lines in door module ECUs subject to ESD and battery reversal events. IC Role / Device Role / Timing Role: Unidirectional TVS on VBAT rail and LIN transceiver pins to absorb ±30 kV contact ESD per IEC 61000-4-2. Use Value: Sub-µA leakage at 12 V prevents standby current drain; 150 °C rating supports under-dash mounting near HVAC ducts. |
| Telecom Remote Radio Unit (RRU) | LED Streetlight Driver |
|
Use Scenario: Outdoor base station power interface subjected to induced lightning surges on PoE or DC feed lines. IC Role / Device Role / Timing Role: First-stage protection before DC-DC isolation stage; coordinates with MOVs and gas discharge tubes in multi-stage architecture. Use Value: 10 kW (8/20 µs) capability handles fast-rising induced surges; UL94 V0 housing meets EN 60950-1 flame safety. |
Use Scenario: Constant-current LED driver input subjected to grid-switching transients and capacitor discharge spikes. IC Role / Device Role / Timing Role: Parallel-connected TVS across bulk capacitor to suppress >1 kV transients without affecting steady-state regulation. Use Value: 19.9 V clamping ensures MOSFET gate drivers remain within safe SOA; low capacitance (<100 pF) avoids EMI coupling into feedback loop. |
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-TR | Lower PPP (600 W vs. 1500 W); same VRM/VBR but higher VCL (21.2 V @ 28.3 A) | Restricted to lower-energy surges (e.g., board-level ESD only); unsuitable for mains-connected inputs | Select when space-constrained SMB package is required and surge threat level is limited to IEC 61000-4-2 only. |
| 1.5KE12A | Through-hole DO-201 package; identical electrical specs but 10× higher thermal resistance (RθJA ≈ 100 °C/W vs. ~50 °C/W for SMC) | Requires larger PCB area and heatsinking; incompatible with automated SMT assembly | Choose only for legacy through-hole designs where rework flexibility outweighs power density and thermal performance. |
Compared with SMBJ12A-TR and 1.5KE12A, SMCJ12A-TR delivers superior energy handling in compact SMT form factor, enabling robust protection in space-limited, high-temperature industrial and automotive applications without compromising thermal reliability or manufacturability.
Availability
SMCJ12A-TR is available at Aetrix Electronics and suitable for industrial power supply input protection, automotive body control modules, telecom remote radio units, and LED streetlight drivers requiring stable component supply and long-term lifecycle assurance.
Supply support for SMCJ12A-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.
SMCJ series belongs to ST's high-power TVS portfolio, engineered specifically for robust, high-temperature ESD and surge protection in mission-critical power and communication interfaces where reliability under thermal stress is non-negotiable.
FAQ
What is the maximum clamping voltage of SMCJ12A-TR under a 10/1000 µs surge?
The maximum clamping voltage (VCL) is 19.9 V at 79 A peak pulse current for a 10/1000 µs waveform, measured at 25 °C ambient. This value increases with junction temperature at a coefficient of 10⁻⁴ /°C, reaching approximately 21.2 V at Tj = 150 °C using the formula VCL(Tj) = VCL(25°C) × [1 + αT × (Tj − 25)].
Is SMCJ12A-TR bidirectional or unidirectional?
SMCJ12A-TR is unidirectional - it conducts only in reverse bias during positive transients on the cathode side. Its counterpart SMCJ12CA-TR is bidirectional and marked "FBH" per ST's ordering table. Polarity must be verified via marking (FUH) and schematic symbol to avoid incorrect placement.
Does SMCJ12A-TR meet automotive AEC-Q200 requirements?
No - SMCJ12A-TR is not AEC-Q200 qualified. While it operates up to 150 °C and meets IEC 61000-4-2/4-4, ST does not list it in their AEC-Q200-certified TVS portfolio. For automotive-grade qualification, consider ST's Automotive Qualified SMAJ or SMF series, which undergo stress testing per AEC-Q200 Rev D.
What is the recommended PCB footprint for SMCJ12A-TR?
The recommended footprint matches IPC7531 and JEDEC MO-136 standards: pad length 5.11 mm, pad width 3.14 mm, center-to-center spacing 8.19 mm, with 1.54 mm solder mask clearance. Thermal relief via ≥2 cm² copper pour per pad reduces RθJA to ~50 °C/W, critical for sustaining 1250 W at Tj = 150 °C.
SMCJ12A-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):
- 12V
- Voltage - Breakdown (Min):
- 13.3V
- Voltage - Clamping (Max) @ Ipp:
- 25.3V
- Current - Peak Pulse (10/1000µs):
- 394A (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
SMCJ12A-TR FAQ
1.How can I place an order for SMCJ12A-TR through Aetrix?
Please submit a Request for Quotation (RFQ) for SMCJ12A-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 SMCJ12A-TR reliable?
The price and inventory of SMCJ12A-TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMCJ12A-TR is usually 5 days.
3.What payment methods are accepted for SMCJ12A-TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMCJ12A-TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMCJ12A-TR?
SMCJ12A-TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMCJ12A-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 SMCJ12A-TR?
For technical support, including SMCJ12A-TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMCJ12A-TR requirements.
6.How does Aetrix verify that SMCJ12A-TR is sourced from the original manufacturer or authorized distributors?
All SMCJ12A-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 SMCJ12A-TR meets industry standards.
7.What is the process for return or replacement of SMCJ12A-TR?
All SMCJ12A-TR units undergo pre-shipment inspection (PSI). If there is an issue with SMCJ12A-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 SMCJ12A-TR part is unused and in its original packaging.
Return procedure for SMCJ12A-TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMCJ12A-TR Tags
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