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

STMicroelectronics SM15T22CAY

Name: SM15T22CAY
Brand: STMicroelectronics
SKU: SM15T22CAY
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: SM15T22CAY

Manufacturer:: STMicroelectronics

Category:: TVS Diodes

Package:: DO-214AB, SMC

Datasheet:: SM15T22CAY.pdf

Description:: TVS DIODE 18.8VWM 39.3VC SMC

Quantity:: RFQ Add To RFQ list

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Inventory:5,974

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Product details

Overview

SM15T22CAY from STMicroelectronics is a bidirectional automotive-grade transient voltage suppressor (TVS) diode in SMC package, designed for ISO 7637-2 pulse protection in 12 V vehicle systems. It features 22 V nominal breakdown voltage (V_BR = 18.8–23.1 V), 30.6 V clamping voltage (V_CL) at 49 A (10/1000 µs), 1500 W peak pulse power, and AEC-Q101 qualification for under-hood reliability.

For engineers reviewing the SM15T22CAY datasheet, SM15T22CAY pinout, SM15T22CAY application, or SM15T22CAY equivalent, this device is selected for high-reliability automotive surge suppression where low leakage (0.2 µA @ 25 °C), high junction temperature operation (T_j up to +150 °C), and bidirectional ESD immunity (±30 kV per ISO 10605) are critical.

Technical Context

This bidirectional TVS uses planar silicon technology to achieve stable V_BR temperature coefficient (α_T = 9.2 × 10⁻⁴/°C) and low dynamic resistance (R_D = 0.153 Ω at 10/1000 µs). Its symmetrical I-V characteristics enable equal clamping in both polarities, supporting robust protection against load dump reversal and ESD transients on data or power lines.

It complies with ISO 7637-2 Pulse 1 (−150 V), Pulse 2a (+112 V), Pulse 3a (−220 V), and Pulse 3b (+150 V), and exceeds IEC 61000-4-2 Level 4 (±30 kV air/contact discharge) with C = 150 pF / R = 330 Ω and C = 330 pF / R = 330 Ω configurations.

Key Specifications

Parameter	Value and Actual Design Meaning
V_BR (min/typ/max)	18.8 / 20.9 / 22 V - ensures reliable turn-on before system overvoltage damages downstream ICs
V_CL @ I_PP = 49 A	30.6 V - limits transient voltage across protected line to safe level during 10/1000 µs surge
I_RM @ V_RM = 18 V	0.2 µA @ 25 °C - minimizes standby current loss in always-on automotive modules
P_PP (10/1000 µs)	1500 W - sustains high-energy transients without degradation in engine control or body electronics
T_j max	+150 °C - enables direct mounting near heat sources (e.g., powertrain ECUs) without derating
Package	SMC (DO-214AB) - industry-standard surface-mount outline with IPC7531-compliant footprint
AEC-Q101	Qualified - validated for automotive use including temperature cycling, humidity bias, and mechanical shock

Pinout & Package

The SM15T22CAY is a two-terminal bidirectional TVS diode in SMC (DO-214AB) package. The cathode/anode polarity is non-applicable due to symmetrical construction; both terminals serve as interchangeable surge current paths.

Pin/Terminal	Circuit Role	Design Meaning
Anode (Terminal 1)	Surge current entry (negative polarity)	Accepts reverse transient energy during ISO 7637-2 Pulse 1 or Pulse 3a events
Cathode (Terminal 2)	Surge current entry (positive polarity)	Accepts forward transient energy during ISO 7637-2 Pulse 2a or Pulse 3b events

Key Features

Feature	Design Value
Bidirectional clamping symmetry	Identical V_BR and V_CL in both directions - eliminates need for polarity-aware layout in CAN/LIN bus protection
Low dynamic resistance	R_D = 0.153 Ω - reduces clamping voltage overshoot during fast-rising transients (e.g., ESD)
High-temperature leakage stability	1 µA @ 85 °C - maintains signal integrity in cabin or powertrain modules operating continuously at elevated ambient
Automotive-grade solderability	Matte tin plating, J-STD-002/E3 compliant - ensures reliable reflow attachment on FR4 PCBs with 70 µm Cu
ISO 7637-2 compliance	Validated for Pulses 1, 2a, 3a, 3b - covers full range of battery-line surges in 12 V vehicles

Applications

Infotainment Power Rail Protection

CAN FD Transceiver ESD Guard

Use Scenario: Protecting 12 V supply input to head unit MCU and display driver ICs against load dump and jump-start surges.

IC Role / Device Role / Timing Role: Bidirectional TVS placed upstream of DC-DC converter input to clamp transients before regulation stage.

Use Value: Limits V_IN to ≤30.6 V during 1500 W pulses, preventing regulator latch-up and preserving boot sequence integrity.

Use Scenario: Shielding CAN FD physical layer transceivers from ESD events on vehicle harnesses.

IC Role / Device Role / Timing Role: Low-capacitance (≈200 pF @ 0 V) bidirectional clamp across CANH–CANL differential pair.

Use Value: Clamps ±30 kV contact discharge without distorting 5 Mbps FD signaling waveform or increasing bit error rate.

Body Control Module (BCM) LIN Bus

ADAS Camera Power Input

Use Scenario: Securing LIN slave nodes (e.g., door module sensors) against battery disconnection spikes.

IC Role / Device Role / Timing Role: TVS connected between LIN bus and ground, leveraging bidirectional symmetry for polarity-agnostic installation.

Use Value: Survives −220 V Pulse 3a (12 V system) while maintaining <1 µA leakage at 85 °C for low-power sleep mode.

Use Scenario: Safeguarding 5 V camera module power rail from ignition-induced transients in rear-view or surround-view systems.

IC Role / Device Role / Timing Role: Secondary TVS after primary fuse, absorbing residual energy that passes through front-end filtering.

Use Value: Delivers 1250 W clamping capability at T_j = 150 °C - critical for compact, sealed camera housings with limited thermal dissipation.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
SMAJ22CA	Lower P_PP (400 W), higher V_CL (35.5 V @ 11.3 A), SMA package	Not AEC-Q101 qualified; suitable only for non-automotive industrial use	Select when cost sensitivity outweighs automotive qualification and surge margin requirements
1.5KE22CA	Higher V_CL (33.2 V @ 45.2 A), axial DO-201 package, no AEC-Q101	Larger footprint, unsuitable for automated SMT assembly; lacks ISO 7637-2 validation	Choose only for legacy through-hole designs where board space and qualification are secondary

Compared with SMAJ22CA and 1.5KE22CA, SM15T22CAY delivers 3.75× higher peak power, 4.9× lower dynamic resistance, and certified AEC-Q101 reliability - making it the sole choice for new automotive designs requiring ISO 7637-2 Pulse 3a/3b immunity and long-term under-hood stability.

Availability

SM15T22CAY is available at Aetrix Electronics and suitable for automotive infotainment systems, ADAS camera modules, and body control units requiring stable component supply with full traceability and lifecycle management.

Supply support for SM15T22CAY 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 automotive, industrial, and power discrete technologies with vertical manufacturing capabilities.

The SM15Txx series belongs to ST's automotive-qualified TVS portfolio, engineered specifically for robust transient suppression in 12 V and 24 V vehicle networks - emphasizing AEC-Q101 reliability, ISO 7637-2 compliance, and high-temperature operational stability.

FAQ

What is the maximum clamping voltage of SM15T22CAY under a 10/1000 µs surge?

The maximum clamping voltage (V_CL) is 30.6 V at 49 A for a 10/1000 µs waveform, measured at T_amb = 25 °C. This value increases with junction temperature per α_T = 9.2 × 10⁻⁴/°C, reaching ~32.1 V at T_j = 125 °C using the formula V_CL(T_j) = V_CL(25 °C) × [1 + α_T × (T_j − 25)].

Is SM15T22CAY unidirectional or bidirectional, and how does that affect circuit placement?

SM15T22CAY is bidirectional, indicated by the "CA" suffix. Its symmetrical I-V curve allows placement across any two nodes requiring surge suppression - such as CANH–CANL, LIN–GND, or V_BAT–GND - without regard to polarity. No orientation marking is required on PCB silkscreen.

Does SM15T22CAY meet ISO 10605 ESD requirements for automotive interiors?

Yes - it exceeds ISO 10605 Level 4 for both air and contact discharge (±30 kV) with C = 150 pF/R = 330 Ω and C = 330 pF/R = 330 Ω test conditions. Its low leakage (0.2 µA @ 25 °C) and stable V_BR ensure consistent performance across cabin temperature ranges (−40 to +85 °C).

What is the recommended PCB footprint and thermal relief for SM15T22CAY?

The official footprint is 5.11 mm × 8.19 mm (201 mil × 322 mil) with 1.54 mm pad extensions, per Figure 18 in DS6928 Rev 6. Thermal relief requires ≥3 cm² total copper area under both leads (R_th(j-a) ≈ 40 °C/W at 3.5 cm²) to sustain 1500 W pulses without exceeding T_j = 150 °C.

SM15T22CAY Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Package/Case:: DO-214AB, SMC

Series:: SM15TY, TRANSIL™

Packaging:: Tape & Reel (TR)

Product Status:: Active

Type:: Zener

Unidirectional Channels:: -

Bidirectional Channels:: 1

Voltage - Reverse Standoff (Typ):: 18.8V

Voltage - Breakdown (Min):: 20.9V

Voltage - Clamping (Max) @ Ipp:: 39.3V

Current - Peak Pulse (10/1000µs):: 254A (8/20µs)

Power - Peak Pulse:: 1500W (1.5kW)

Power Line Protection:: No

Applications:: -

Capacitance @ Frequency:: -

Operating Temperature:: -40°C ~ 150°C (TJ)

Grade:: Automotive

Qualification:: AEC-Q101

Mounting Type:: Surface Mount

Supplier Device Package:: SMC

SM15T22CAY FAQ

1.How can I place an order for SM15T22CAY through Aetrix?

Please submit a Request for Quotation (RFQ) for SM15T22CAY 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 SM15T22CAY reliable?

The price and inventory of SM15T22CAY are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SM15T22CAY is usually 5 days.

3.What payment methods are accepted for SM15T22CAY?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM15T22CAY transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for SM15T22CAY?

SM15T22CAY orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your SM15T22CAY 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 SM15T22CAY?

For technical support, including SM15T22CAY datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM15T22CAY requirements.

6.How does Aetrix verify that SM15T22CAY is sourced from the original manufacturer or authorized distributors?

All SM15T22CAY 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 SM15T22CAY meets industry standards.

7.What is the process for return or replacement of SM15T22CAY?

All SM15T22CAY units undergo pre-shipment inspection (PSI). If there is an issue with SM15T22CAY, 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 SM15T22CAY part is unused and in its original packaging.

Return procedure for SM15T22CAY:

1.Submit a request within 90 days.

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

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