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

STMicroelectronics SM30T7.5AY

Name: SM30T7.5AY
Brand: STMicroelectronics
SKU: SM30T7.5AY
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: SM30T7.5AY

Manufacturer:: STMicroelectronics

Category:: TVS Diodes

Package:: DO-214AB, SMC

Datasheet:: SM30T7.5AY.pdf

Description:: TVS DIODE 6.5VWM 11.2VC SMC

Quantity:: RFQ Add To RFQ list

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Inventory:8,889

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Product details

Overview

SM30T7.5AY from STMicroelectronics is a unidirectional automotive-grade transient voltage suppression (TVS) diode in SMC package, designed for ISO 7637-2 pulse protection in 12 V automotive systems. It features a 7.5 V nominal breakdown voltage (V_BR = 7.2–7.9 V), 11.2 V clamping voltage (V_CL) at 268 A (10/1000 µs), 3000 W peak pulse power, and AEC-Q101 qualification for under-hood reliability.

For engineers reviewing the SM30T7.5AY datasheet, SM30T7.5AY pinout, SM30T7.5AY application, or SM30T7.5AY equivalent, this device serves as a primary surge protector for CAN transceivers, LIN bus interfaces, and body control modules where low leakage (≤0.2 µA at 25 °C), high junction temperature operation (T_j up to +175 °C), and robust ESD immunity (±30 kV contact/air per ISO 10605) are required.

Technical Context

The SM30T7.5AY employs planar silicon junction technology to achieve stable V_BR with low dynamic resistance (R_D = 4.77 mΩ) and minimal capacitance-critical for preserving signal integrity on high-speed automotive buses. Its unidirectional configuration enables DC-biased protection of positive-rail circuits without reverse conduction path concerns.

It meets stringent automotive surge standards: ISO 7637-2 Pulse 1 (−150 V), Pulse 2a (+112 V), Pulse 3a (−220 V), and Pulse 3b (+150 V), while sustaining 30 kV ESD per ISO 10605 (C = 150 pF / 330 Ω and C = 330 pF / 330 Ω) and IEC 61000-4-4 Level 4 (4 kV).

Key Specifications

Parameter	Value and Actual Design Meaning
V_BR (min/typ/max)	7.2 V / 7.5 V / 7.9 V - ensures reliable turn-on before downstream IC damage at 12 V system rail
V_CL @ 268 A (10/1000 µs)	11.2 V - clamps transients below 12 V logic threshold, protecting 5 V or 3.3 V interface ICs
I_PP (10/1000 µs)	268 A - supports full ISO 7637-2 Pulse 1 energy (−150 V into 2 Ω load)
Leakage current I_R	≤0.2 µA at V_RM = 6.5 V - avoids battery drain in always-on vehicle modules
T_j max	+175 °C - enables placement near hot engine compartments without derating
Package	SMC (DO-214AB) - JEDEC-registered surface-mount outline with 7.75–8.15 mm width, optimized for thermal dissipation on FR4 PCB
AEC-Q101	Qualified - validated for automotive temperature cycling, humidity, and mechanical shock per stress test requirements

Pinout & Package

SM30T7.5AY uses the standard SMC (DO-214AB) package: 2-terminal unidirectional TVS with cathode-marked end. The package measures 5.55–6.25 mm in length (D), 7.75–8.15 mm in width (E), and 2.45 mm max height (A2), with matte tin-plated leads compliant with J-STD-002 and RoHS.

Pin/Terminal	Circuit Role	Design Meaning
Anode	Ground reference terminal	Connected to chassis or system ground; carries full surge current during clamping
Cathode	Protected line terminal	Connected to protected node (e.g., CAN_H); blocks reverse voltage until V_BR exceeded

Key Features

Feature	Design Value
Peak pulse power	3000 W (10/1000 µs) - handles full ISO 7637-2 Pulse 1 energy without failure
ESD robustness	±30 kV air/contact discharge (ISO 10605) - exceeds automotive infotainment and ADAS ESD requirements
Low dynamic resistance	4.77 mΩ - minimizes clamping voltage rise under high-current surges
High-temperature operation	Rated to +175 °C junction - eliminates need for thermal derating in under-hood ECUs
Low leakage	≤0.2 µA at 6.5 V - prevents measurable current draw in sleep-mode vehicle networks

Applications

Infotainment Head Unit Power Input

CAN FD Transceiver Protection

Use Scenario: Protects 12 V input stage of head unit against load dump and alternator transients.

IC Role / Device Role / Timing Role: Primary front-end TVS clamping device placed before DC-DC converter input.

Use Value: Clamps to 11.2 V at 268 A, preventing overvoltage damage to buck controller and enabling compliance with ISO 7637-2 Pulse 5b (load dump).

Use Scenario: Shields high-speed CAN FD physical layer from ESD and coupled noise on vehicle harness.

IC Role / Device Role / Timing Role: Unidirectional shunt protector on CAN_H line referenced to ground.

Use Value: Low capacitance and 4.77 mΩ R_D preserve signal edge integrity up to 5 Mbps while suppressing ±30 kV ESD events.

Body Control Module (BCM) LIN Bus

ADAS Camera Power Rail

Use Scenario: Secures LIN transceiver supply (12 V) against battery disconnect spikes and relay bounce.

IC Role / Device Role / Timing Role: Standoff protector on V_CC rail with 6.5 V working voltage margin.

Use Value: 0.2 µA leakage ensures <1 µA total standby current across multiple LIN nodes, meeting OEM sleep-current budgets.

Use Scenario: Guards 12 V camera module power input against engine cranking dips and ignition noise.

IC Role / Device Role / Timing Role: First-line transient suppressor upstream of LDO regulator.

Use Value: 175 °C T_j rating allows direct mounting on camera housing near heat-generating image sensor.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
SMAJ7.5A	Lower PPP (400 W), higher V_CL (12.5 V @ 32.4 A), SMC-compatible but not AEC-Q101 qualified	Not suitable for automotive under-hood use; limited to industrial or consumer-grade 12 V inputs	Select only if AEC-Q101 is not required and surge energy is ≤100 mJ
TPSMD7.5	Same SMC package, AEC-Q101 qualified, but higher V_CL (12.0 V @ 250 A) and lower I_PP (250 A)	Marginally adequate for ISO 7637-2 Pulse 1; insufficient for Pulse 3a (−220 V)	Prefer SM30T7.5AY when full ISO 7637-2 compliance and 268 A I_PP are mandatory

Compared with SMAJ7.5A and TPSMD7.5, SM30T7.5AY delivers 7.5× higher peak pulse power, tighter V_CL tolerance, and verified AEC-Q101 performance-making it the only choice for production automotive ECUs requiring full ISO 7637-2 and ISO 10605 compliance at 12 V system level.

Availability

SM30T7.5AY is available at Aetrix Electronics and suitable for automotive electronic control units, infotainment systems, and advanced driver-assistance systems requiring stable component supply across multi-year vehicle production cycles.

Supply support for SM30T7.5AY 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, designing and manufacturing microcontrollers, power devices, sensors, and analog ICs for automotive, industrial, and consumer markets.

The SM30TxxAY series belongs to ST's automotive-grade TVS portfolio, engineered specifically for robust transient suppression in 12 V and 24 V vehicle electrical architectures-including CAN, LIN, FlexRay, and camera power rails-where AEC-Q101 reliability and ISO-compliant surge handling are non-negotiable.

FAQ

What is the maximum clamping voltage of SM30T7.5AY under a 10/1000 µs surge?

The maximum clamping voltage (V_CL) is 11.2 V at 268 A for a 10/1000 µs waveform, measured at T_amb = 25 °C. This value increases with junction temperature at a coefficient of 4.77 mΩ × I_PP, and must be verified using the formula V_CL(T_j) = V_CL(25 °C) × [1 + α_T × (T_j − 25)], where α_T = 4.77 × 10⁻³/°C per datasheet Table 2.

Is SM30T7.5AY bidirectional or unidirectional?

SM30T7.5AY is unidirectional. Its marking "3AACY" (per Table 6) and part number suffix "AY" confirm unidirectional polarity. It conducts only during positive transients on the cathode side and blocks reverse voltage up to −6.5 V (V_RM), making it suitable for single-polarity 12 V rail protection-not for AC or differential bus lines like RS-485.

Can SM30T7.5AY replace SMAJ7.5A in an existing design?

No direct replacement is advised without revalidation. While both use SMC packages and share V_BR ≈ 7.5 V, SM30T7.5AY delivers 3000 W peak power (vs. 400 W) and AEC-Q101 qualification-requiring updated thermal layout, surge test requalification, and verification of PCB copper area per Figure 12 (R_th(j-a) vs. copper area). Layout changes may be needed to manage higher energy dissipation.

Does SM30T7.5AY meet ISO 7637-2 Pulse 5b (load dump) requirements?

Yes-SM30T7.5AY is rated for ISO 7637-2 Pulse 5b (load dump) with Us = 87 V and tp = 150 ms/400 ms, as confirmed by Figures 18–22 in DS8599. Its 3000 W rating and low R_D enable safe clamping of sustained overvoltage events typical of alternator regulation failure, provided board layout follows ST's recommended footprint (Figure 24) and copper area ≥3 cm² per lead.

SM30T7.5AY Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Package/Case:: DO-214AB, SMC

Series:: SM30TY, TRANSIL™

Packaging:: Tape & Reel (TR)

Product Status:: Active

Type:: Zener

Unidirectional Channels:: 1

Bidirectional Channels:: -

Voltage - Reverse Standoff (Typ):: 6.5V

Voltage - Breakdown (Min):: 7.13V

Voltage - Clamping (Max) @ Ipp:: 11.2V

Current - Peak Pulse (10/1000µs):: 268A

Power - Peak Pulse:: 3000W (3kW)

Power Line Protection:: No

Applications:: -

Capacitance @ Frequency:: -

Operating Temperature:: -55°C ~ 175°C (TJ)

Grade:: Automotive

Qualification:: AEC-Q101

Mounting Type:: Surface Mount

Supplier Device Package:: SMC

SM30T7.5AY FAQ

1.How can I place an order for SM30T7.5AY through Aetrix?

Please submit a Request for Quotation (RFQ) for SM30T7.5AY 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 SM30T7.5AY reliable?

The price and inventory of SM30T7.5AY are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SM30T7.5AY is usually 5 days.

3.What payment methods are accepted for SM30T7.5AY?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM30T7.5AY transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for SM30T7.5AY?

SM30T7.5AY orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your SM30T7.5AY 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 SM30T7.5AY?

For technical support, including SM30T7.5AY datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM30T7.5AY requirements.

6.How does Aetrix verify that SM30T7.5AY is sourced from the original manufacturer or authorized distributors?

All SM30T7.5AY 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 SM30T7.5AY meets industry standards.

7.What is the process for return or replacement of SM30T7.5AY?

All SM30T7.5AY units undergo pre-shipment inspection (PSI). If there is an issue with SM30T7.5AY, 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 SM30T7.5AY part is unused and in its original packaging.

Return procedure for SM30T7.5AY:

1.Submit a request within 90 days.

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

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