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STMicroelectronics SM15T68A
- Part No.:
- SM15T68A
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SM15T68A.pdf
- Description:
- TVS DIODE 58.1VWM 121VC SMC
- Quantity:
- Payment:
- Shipping:
Inventory:2,494
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Product details
Overview
SM15T68A from STMicroelectronics is a unidirectional 1500 W transient voltage suppression diode in SMC package, designed for IEC 61000-4-2 ESD (30 kV air/contact) and IEC 61000-4-4 surge (4 kV level 4) protection of DC power rails and signal lines. It features 68 V standoff voltage (VRWM), 92 V clamping voltage at 16.3 A (10/1000 µs), and 0.2 µA leakage at 25 °C.
For engineers reviewing the SM15T68A datasheet, SM15T68A pinout, SM15T68A application, or SM15T68A equivalent, this TVS diode is selected for high-reliability DC input protection in industrial power supplies, telecom interfaces, and automotive body electronics where low leakage, high Tj (150 °C), and stable clamping under repeated surges are critical.
Technical Context
The SM15T68A uses planar junction technology to achieve low leakage (<0.2 µA at 25 °C) and stable VBR drift (αT = 10.4 × 10−4/°C). Its dynamic resistance (RD = 1.26 Ω) ensures predictable clamping across temperature and pulse duration.
Rated for 1500 W (10/1000 µs) at Tj = 25 °C and up to 1250 W at Tj = 150 °C, it maintains compliance with UL 497B, IEC 61000-4-2/4-4, and JEDEC J-STD-020 MSL Level 1 - enabling reflow-compatible PCB integration without derating concerns.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 68 V - maximum continuous reverse working voltage before breakdown; sets operating margin for 48–60 V DC systems. |
| VBR (min) | 58.1 V at 1 mA - guaranteed breakdown onset; ensures reliable triggering above system nominal voltage. |
| VCL @ IPP = 16.3 A | 92 V - clamped voltage during 10/1000 µs surge; defines worst-case overvoltage seen by downstream circuitry. |
| IPP (10/1000 µs) | 16.3 A - peak pulse current capability at rated power; determines minimum series impedance required for full protection. |
| RD | 1.26 Ω - dynamic resistance; governs voltage rise per amp of surge current beyond IPP. |
| IR @ VRWM | 0.2 µA at 25 °C - ultra-low leakage; minimizes standby power loss and avoids false triggering in high-impedance sensing nodes. |
| Tj max | 150 °C - maximum junction temperature; enables operation in enclosed enclosures or near heat sources without thermal shutdown. |
Pinout & Package
SM15T68A is housed in an SMC (DO-214AB) surface-mount package with two terminals: Cathode (marked side) and Anode. The package complies with IPC7531 footprint and JEDEC registered outline, featuring 7.75–8.15 mm body width (E), 5.55–6.25 mm length (D), and 1.90–2.45 mm height (A1).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (marked end) | Surge current sink | Connected to protected line; conducts transient energy to ground when VAK exceeds VBR. |
| Anode | Reference node | Typically tied to system ground or lower-potential rail; completes conduction path during overvoltage events. |
Key Features
| Feature | Design Value |
|---|---|
| 1500 W peak pulse power (10/1000 µs) | Supports robust protection against lightning-induced surges in industrial 48 V DC distribution systems. |
| 0.2 µA leakage at 25 °C | Enables use in battery-backed or ultra-low-power monitoring circuits without measurable drain. |
| 10.4 × 10−4/°C VBR tempco | Ensures predictable clamping voltage shift across −55 to +150 °C, simplifying thermal design margins. |
| UL 497B certified (QVGQ2.E136224) | Validates suitability for primary-side telecom and industrial interface protection per safety standards. |
| JEDEC J-STD-020 MSL Level 1 | Permits unlimited floor life and standard reflow without baking, reducing manufacturing overhead. |
Applications
| Industrial Power Input Protection | Telecom DC Feeder Protection |
|---|---|
|
Use Scenario: 48 V DC input stage of programmable logic controllers (PLCs) exposed to field wiring transients. IC Role / Device Role / Timing Role: Unidirectional TVS diode placed between DC+ and chassis ground to clamp induced surges before they reach DC-DC converters. Use Value: Limits voltage to ≤92 V during 16.3 A surges, preventing damage to 100 V-rated input capacitors and MOSFETs. |
Use Scenario: -48 V DC power feeders in central office equipment subject to lightning coupling on long cable runs. IC Role / Device Role / Timing Role: Standoff-rated TVS on the negative rail, referenced to ground, to absorb common-mode surges without disrupting bias. Use Value: Maintains <0.2 µA leakage at elevated ambient temperatures, avoiding false trips in fault-monitoring circuits. |
| Automotive Body Control Module (BCM) | Smart Meter Power Supply |
|
Use Scenario: 12 V auxiliary supply input in BCMs subjected to ISO 7637-2 pulse 1/2a/3a and ESD events. IC Role / Device Role / Timing Role: Primary overvoltage clamp on fused battery line, coordinated with upstream fuse timing to avoid nuisance blowing. Use Value: Delivers 1250 W surge capability at 150 °C junction temperature, matching under-hood thermal environments. |
Use Scenario: AC/DC adapter output stage in utility smart meters requiring long-term reliability and metering accuracy. IC Role / Device Role / Timing Role: Final-stage TVS on regulated 5 V or 3.3 V rail protecting metrology ICs and RTCs from back-fed transients. Use Value: Ultra-low leakage preserves battery backup runtime during extended power outages without calibration drift. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar unidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ68A (Bourns) | Same 68 V VRWM, but 600 W rating (10/1000 µs); RD = 2.2 Ω; higher leakage (1 µA). | Limited to lower-energy surges; unsuitable for sustained 1500 W threats like indirect lightning. | Select only if system-level testing confirms 600 W sufficiency and thermal budget allows higher clamping. |
| P6SMB68A (Littelfuse) | Identical 68 V VRWM and 1500 W rating, but VCL = 110 V @ 13.7 A; RD = 1.8 Ω; Tj max = 175 °C. | Higher clamping increases stress on downstream components; wider VBR tolerance (±10 % vs ±5 %). | Prefer only when higher junction temperature margin (175 °C) outweighs need for tighter clamping control. |
Compared with SMBJ68A and P6SMB68A, SM15T68A delivers superior clamping precision (92 V vs ≥110 V), lower dynamic resistance (1.26 Ω), and lower leakage (0.2 µA), making it optimal for high-density, thermally constrained, or metrology-critical designs where voltage margin is tight.
Availability
SM15T68A is available at Aetrix Electronics and suitable for industrial power input protection, telecom DC feeder protection, automotive body control modules, and smart meter power supplies requiring stable component supply across multi-year production cycles.
Supply support for SM15T68A 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, delivering silicon solutions for automotive, industrial, and power management applications.
SM15T68A belongs to the SM15T series of planar TVS diodes engineered specifically for high-reliability DC rail protection in harsh environments where low leakage, precise clamping, and thermal stability are non-negotiable.
FAQ
What is the maximum clamping voltage of SM15T68A under a 10/1000 µs surge?
The maximum clamping voltage (VCL) is 92 V at 16.3 A for a 10/1000 µs waveform, measured at Tj = 25 °C. This value increases with junction temperature at a rate defined by αT = 10.4 × 10−4/°C, reaching approximately 98 V at Tj = 125 °C.
Can SM15T68A be used in bidirectional configurations?
No - SM15T68A is unidirectional (anode-cathode polarity). For bidirectional protection, ST offers the pin-compatible SM15T68CA variant, which provides symmetrical clamping for AC-coupled or floating signal lines.
Does SM15T68A meet automotive AEC-Q200 requirements?
SM15T68A is not AEC-Q200 qualified. It is rated for industrial and telecom applications with Tj = −55 to +150 °C, but lacks the stress-test validation (e.g., temperature cycling, board flex) required for automotive qualification.
What is the recommended PCB footprint for SM15T68A?
The recommended footprint follows IPC7531 and JEDEC DO-214AB standards: 8.19 mm pad length, 3.14 mm pad width, 5.11 mm center-to-center spacing, and 1.54 mm solder mask opening per pad - optimized for thermal dissipation and reflow yield per ST's DS0683 Rev 8.
SM15T68A Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- DO-214AB, SMC
- Series:
- SM15T, TRANSIL™
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 58.1V
- Voltage - Breakdown (Min):
- 64.6V
- Voltage - Clamping (Max) @ Ipp:
- 121V
- Current - Peak Pulse (10/1000µs):
- 83A (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
SM15T68A FAQ
1.How can I place an order for SM15T68A through Aetrix?
Please submit a Request for Quotation (RFQ) for SM15T68A 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 SM15T68A reliable?
The price and inventory of SM15T68A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SM15T68A is usually 5 days.
3.What payment methods are accepted for SM15T68A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM15T68A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SM15T68A?
SM15T68A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SM15T68A 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 SM15T68A?
For technical support, including SM15T68A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM15T68A requirements.
6.How does Aetrix verify that SM15T68A is sourced from the original manufacturer or authorized distributors?
All SM15T68A 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 SM15T68A meets industry standards.
7.What is the process for return or replacement of SM15T68A?
All SM15T68A units undergo pre-shipment inspection (PSI). If there is an issue with SM15T68A, 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 SM15T68A part is unused and in its original packaging.
Return procedure for SM15T68A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SM15T68A Tags
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