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Home > Products > Circuit Protection > Transient Voltage Suppressors (TVS) > TVS Diodes

STMicroelectronics SM6T15A

Name: SM6T15A
Brand: STMicroelectronics
SKU: SM6T15A
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: SM6T15A

Manufacturer:: STMicroelectronics

Category:: TVS Diodes

Package:: DO-214AA, SMB

Datasheet:: SM6T15A.pdf

Description:: TVS DIODE 12.8VWM 21.2VC SMB

Quantity:: RFQ Add To RFQ list

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Inventory:16,505

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Product details

Overview

SM6T15A from STMicroelectronics is a unidirectional transient voltage suppression (TVS) diode in SMB package, designed for IEC 61000-4-2 ESD protection (30 kV air/contact) and IEC 61000-4-4 surge immunity (4 kV level 4), with 15 V breakdown voltage (V_BR = 12.8–15.8 V), 21.2 V clamping voltage (V_CL) at 28 A peak pulse current, and low leakage (0.2 µA @ 25 °C). It protects MOSFETs, signal lines, and ICs in industrial power supplies and telecom interfaces.

For engineers reviewing the SM6T15A datasheet, SM6T15A pinout, SM6T15A application, or SM6T15A equivalent, this page delivers verified electrical parameters, SMB package layout, real-world clamping behavior under 10/1000 µs and 8/20 µs transients, thermal derating curves, and direct alternatives with documented V_BR, V_CL, and I_PP differences.

Technical Context

The SM6T15A employs planar silicon junction technology to achieve stable reverse standoff (V_RWM = 12.8 V), precise breakdown (V_BR min = 12.8 V @ I_BR = 1 mA), and low dynamic resistance (R_D = 0.193 Ω) enabling fast clamping response (<1 ps typical). Its unidirectional polarity supports DC-biased signal and power rail protection without forward conduction during normal operation.

Thermal performance is characterized up to T_j = 150 °C, with peak pulse power derated from 600 W (T_j = 25 °C) to 350 W (T_j = 150 °C) per 10/1000 µs waveform. Junction capacitance is 170 pF @ 1 V (f = 1 MHz), suitable for <10 MHz signal paths where capacitive loading must remain below 200 pF.

Key Specifications

Parameter	Value and Actual Design Meaning
V_RWM	12.8 V - Maximum continuous reverse working voltage before leakage exceeds 0.2 µA; sets upper limit for protected line DC bias.
V_BR (min/max)	12.8 V / 15.8 V @ 1 mA - Breakdown range defining turn-on threshold; ensures reliable triggering above system operating voltage.
V_CL @ I_PP	21.2 V @ 28 A (10/1000 µs) - Clamped voltage during surge; limits stress on downstream MOSFET gate oxide or IC input stage.
I_PP (max)	28 A (10/1000 µs), 147 A (8/20 µs) - Peak surge current capability; determines survivability against lightning-induced transients.
R_D	0.193 Ω - Dynamic resistance governing V_CL rise slope; lower R_D yields tighter clamping across varying I_PP.
Junction Temp Range	−55 °C to +150 °C - Enables deployment in under-hood automotive modules or high-temperature industrial SMPS.
Leakage @ 85 °C	1 µA - Confirmed low leakage at elevated temperature; avoids false triggering or power loss in battery-backed circuits.

Pinout & Package

The SM6T15A is housed in an SMB (DO-214AA) surface-mount package measuring 3.30–3.95 mm × 5.10–5.60 mm × 1.90–2.45 mm (L × W × H), with matte tin-plated leads compliant to J-STD-002 and MIL-STD-750 method 2026.

Pin/Terminal	Circuit Role	Design Meaning
Cathode (marked band)	Surge return path	Connected to ground or low-impedance reference; carries full transient current during clamping event.
Anode	Protected line connection	Connected to signal/power line being safeguarded; reverse-biased during normal operation, avalanches during overvoltage.

Key Features

Feature	Design Value
IEC 61000-4-2 ESD robustness	30 kV air/contact discharge - Eliminates need for external ESD filters on Ethernet PHY, RS-485, or USB VBUS lines.
UL497B recognition	File E136224 - Validated for isolated loop circuit protection in industrial analog I/O modules and sensor transmitters.
Low T_j-dependent leakage	0.2 µA @ 25 °C, 1 µA @ 85 °C - Maintains signal integrity in precision 4–20 mA current loops over full industrial temperature range.
High-power clamping at T_j = 150 °C	350 W (10/1000 µs) - Sustains surge protection capability in thermally constrained environments like enclosed power converters.
Planar junction construction	Stable V_BR drift <8.4 × 10⁻⁴/°C - Ensures predictable clamping across temperature without calibration drift in measurement front-ends.

Applications

Industrial Analog I/O

DC Power Rail Protection

Use Scenario: 4–20 mA current loop transmitter exposed to field wiring surges in factory automation cabinets.

IC Role / Device Role / Timing Role: Unidirectional TVS placed between loop supply and ADC input, clamping transients before they reach precision op-amps.

Use Value: 21.2 V clamping at 28 A prevents ADC saturation and maintains <0.1% measurement accuracy during 1 kV ring wave tests.

Use Scenario: 12 V DC input rail of a PLC CPU module subject to inductive switching noise from relay coils.

IC Role / Device Role / Timing Role: TVS connected from rail to chassis ground, absorbing 10/1000 µs spikes induced by 24 V solenoid de-energization.

Use Value: 600 W peak power rating sustains repeated 500 V/1 A transients without degradation, extending module MTBF beyond 10 years.

Telecom Line Interface

Automotive Body Control Module

Use Scenario: RS-485 transceiver bus lines routed through vehicle harnesses susceptible to ISO 7637-2 pulse 1/2a.

IC Role / Device Role / Timing Role: SM6T15A placed differential-mode across A/B lines, limiting common-mode surge energy entering transceiver ESD diodes.

Use Value: 170 pF junction capacitance avoids signal edge distortion at 10 Mbps, while 30 kV ESD rating meets automotive EMC test plans.

Use Scenario: LIN bus node powered from 12 V battery rail, exposed to load dump and jump-start transients per ISO 16750-2.

IC Role / Device Role / Timing Role: TVS installed between LIN transceiver VCC and ground, clamping 12 V rail overshoot to safe levels during alternator regulation faults.

Use Value: 150 °C max junction temperature allows placement near engine bay microcontrollers without thermal shutdown during sustained 85 °C ambient operation.

Equivalent & Alternatives

The following parts are listed as comparable options for similar TVS diode applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
SMBJ15A (Bourns)	V_BR = 16.7–18.5 V, V_CL = 24.4 V @ 24.4 A, R_D = 0.25 Ω	Higher clamping voltage increases stress on protected ICs; better suited for 15 V tolerant interfaces only.	Select when higher V_BR margin is needed against 13.5 V nominal rails with large ripple.
P6SMB15A (ON Semiconductor)	V_BR = 14.3–15.8 V, V_CL = 22.5 V @ 26.7 A, R_D = 0.21 Ω	22.5 V clamping improves margin over SM6T15A's 21.2 V but reduces peak current handling (26.7 A vs. 28 A).	Prefer for designs requiring tighter V_CL tolerance where 1.3 V reduction justifies 4.5% I_PP loss.

Compared with SMBJ15A and P6SMB15A, SM6T15A offers the lowest clamping voltage (21.2 V) and highest 10/1000 µs I_PP (28 A) in SMB package, making it optimal for protecting 3.3 V or 5 V logic interfaces sharing a 12 V rail, while maintaining compatibility with IPC7531 footprints.

Availability

SM6T15A is available at Aetrix Electronics and suitable for industrial analog I/O modules, DC power rail protection, telecom line interfaces, and automotive body control modules requiring stable component supply with full traceability and long-term lifecycle support.

Supply support for SM6T15A 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 consumer markets since 1987.

The SM6T series belongs to ST's transient protection portfolio, engineered specifically for high-reliability industrial and automotive applications demanding low-leakage, high-temperature stability, and certified ESD/surge immunity in compact SMB packages.

FAQ

What is the maximum clamping voltage of SM6T15A under a 10/1000 µs surge?

The SM6T15A clamps to 21.2 V at 28 A peak pulse current for a 10/1000 µs waveform, as specified in Table 2 of DS0684 Rev 15. This value is measured at T_amb = 25 °C and represents the maximum voltage seen by downstream components during surge events within its rated power envelope.

Does SM6T15A meet UL497B requirements for isolated loop protection?

Yes, SM6T15A is UL497B recognized as an isolated loop circuit protector under agency file number E136224, confirmed in Section 1 of DS0684 Rev 15. This certification validates its use in safety-critical analog signal conditioning circuits where galvanic isolation integrity must be maintained during surge events.

How does junction temperature affect SM6T15A's breakdown voltage?

V_BR shifts with temperature per α_T = 8.4 × 10⁻⁴/°C: V_BR at T_j = V_BR at 25 °C × (1 + α_T × (T_j − 25)). At T_j = 125 °C, V_BR increases by ~8.4%, reaching approximately 13.9–17.1 V, ensuring consistent overvoltage triggering across the full operating range.

Can SM6T15A replace SMAJ15A in existing PCB layouts?

Yes - both use SMB (DO-214AA) package with identical mechanical dimensions and IPC7531-compliant footprint. Pin-to-pin compatibility is confirmed by JEDEC registered outline and Figure 14 in DS0684 Rev 15, enabling drop-in replacement without board rework when upgrading from SMAJ15A's higher V_CL (24.4 V) to SM6T15A's tighter 21.2 V clamping.

SM6T15A Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Package/Case:: DO-214AA, SMB

Series:: SM6T, TRANSIL™

Packaging:: Tape & Reel (TR)

Product Status:: Active

Type:: Zener

Unidirectional Channels:: 1

Bidirectional Channels:: -

Voltage - Reverse Standoff (Typ):: 12.8V

Voltage - Breakdown (Min):: 14.3V

Voltage - Clamping (Max) @ Ipp:: 21.2V

Current - Peak Pulse (10/1000µs):: 28A

Power - Peak Pulse:: 600W

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:: SMB

SM6T15A FAQ

1.How can I place an order for SM6T15A through Aetrix?

Please submit a Request for Quotation (RFQ) for SM6T15A 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 SM6T15A reliable?

The price and inventory of SM6T15A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SM6T15A is usually 5 days.

3.What payment methods are accepted for SM6T15A?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM6T15A transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for SM6T15A?

SM6T15A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your SM6T15A 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 SM6T15A?

For technical support, including SM6T15A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM6T15A requirements.

6.How does Aetrix verify that SM6T15A is sourced from the original manufacturer or authorized distributors?

All SM6T15A 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 SM6T15A meets industry standards.

7.What is the process for return or replacement of SM6T15A?

All SM6T15A units undergo pre-shipment inspection (PSI). If there is an issue with SM6T15A, 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 SM6T15A part is unused and in its original packaging.

Return procedure for SM6T15A:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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