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STMicroelectronics SM30T30AY
- Part No.:
- SM30T30AY
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SM30T30AY.pdf
- Description:
- TVS DIODE 26VWM 42.1VC SMC
- Quantity:
- Payment:
- Shipping:
Inventory:1,916
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Product details
Overview
SM30T30AY from STMicroelectronics is an AEC-Q101-qualified unidirectional transient voltage suppression (TVS) diode in SMC package, designed for automotive power line surge protection. It delivers 3000 W peak pulse power (10/1000 µs), clamps at 42.1 V (max) under 71 A surge current, and operates up to 175 °C junction temperature-enabling robust protection of 12 V/24 V battery-fed ECUs against ISO 7637-2 pulses and IEC 61000-4-2 ESD events.
For engineers reviewing the SM30T30AY datasheet, SM30T30AY pinout, SM30T30AY application, or SM30T30AY equivalent, key selection criteria include its 30.4 V nominal breakdown voltage, 0.2 µA leakage at VRM, 9.7 mΩ dynamic resistance, and compliance with ISO 10605 ±30 kV (air/contact discharge) and UL94 V0 flammability rating.
Technical Context
This TVS diode uses planar silicon technology to achieve low leakage and high thermal stability, supporting long-term reliability in harsh automotive environments. Its unidirectional configuration provides forward conduction only during reverse overvoltage transients, with a defined stand-off voltage (VRM = 28.9 V) and precise clamping behavior governed by VBR tolerance (±5%) and temperature coefficient αT = 9.7 × 10⁻⁴ /°C.
The device meets stringent automotive surge immunity standards including ISO 7637-2 Pulse 1 (−150 V), Pulse 2a (+112 V), Pulse 3a (−220 V), and Pulse 3b (+150 V), while maintaining stable performance across −55 °C to +175 °C operating junction temperature range and surviving reflow soldering up to 260 °C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Breakdown Voltage (VBR) | 30.4 V min / 31.9 V max at 1 mA - defines precise overvoltage triggering threshold for 12 V systems |
| Clamping Voltage (VCL) | 42.1 V max at 71 A (10/1000 µs) - limits downstream IC stress during load dump or inductive switching |
| Peak Pulse Power (PPP) | 3000 W (10/1000 µs), 626 W (8/20 µs) - sustains high-energy transients without failure |
| Leakage Current (IRM) | 0.2 µA max at 28.9 V and 25 °C - minimizes standby power loss in always-on vehicle modules |
| Dynamic Resistance (RD) | 9.7 mΩ - ensures low clamping overshoot and fast response to fast-rising surges |
| Junction Temperature Range | −55 °C to +175 °C - supports under-hood placement near engines or power electronics |
| ESD Withstand | ±30 kV (IEC 61000-4-2, 150 pF/330 Ω) - exceeds automotive ESD immunity requirements |
Pinout & Package
SM30T30AY is housed in a JEDEC-registered SMC (DO-214AB) surface-mount package with matte tin-plated leads, footprint-compliant with IPC7531 and optimized for thermal dissipation on FR4 PCBs with ≥3 cm² copper area per lead.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (marked side) | Surge current sink | Connected to protected line; conducts during reverse overvoltage to clamp voltage |
| Anode | Reference ground path | Connected to system ground or battery negative; completes transient current loop |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualification | Validated for automotive-grade reliability across temperature cycling, humidity, and mechanical shock |
| Low leakage current | 0.2 µA at VRM enables use in low-power always-on domains (e.g., body control modules) |
| High junction temperature rating | 175 °C operation allows placement near heat sources without derating |
| ISO 7637-2 compliance | Withstands Pulse 1 (−150 V), Pulse 2a (+112 V), Pulse 3a (−220 V), and Pulse 3b (+150 V) |
| UL94 V0 flammability | Self-extinguishing epoxy housing prevents fire propagation in safety-critical wiring harnesses |
Applications
| Engine Control Unit (ECU) Power Input | Body Control Module (BCM) CAN Bus Interface |
|---|---|
Use Scenario: Protection of 12 V supply rail against alternator load dump and inductive switching spikes. IC Role / Device Role / Timing Role: Unidirectional TVS diode placed between battery input and DC-DC converter input stage. Use Value: Clamps transients to ≤42.1 V, preventing damage to 36 V-rated input capacitors and LDO regulators. | Use Scenario: ESD and burst protection for CANH/CANL lines connected to external connectors. IC Role / Device Role / Timing Role: Standoff protection device mounted at connector entry point before CAN transceiver. Use Value: Absorbs ±30 kV contact discharge without latch-up, preserving signal integrity and bus arbitration timing. |
| Advanced Driver Assistance Systems (ADAS) Camera Power | Electric Power Steering (EPS) Motor Driver Stage |
Use Scenario: Protecting 5 V or 3.3 V camera module power rails from coupled surges via shared harnesses. IC Role / Device Role / Timing Role: Secondary TVS after primary bulk protection, filtering residual fast transients. Use Value: Low 9.7 mΩ RD ensures sub-100 ns response, preventing pixel corruption or frame drop during ESD events. | Use Scenario: Guarding H-bridge gate drivers and current sense amplifiers against motor back-EMF spikes. IC Role / Device Role / Timing Role: High-energy TVS placed across motor terminals and driver supply inputs. Use Value: 3000 W peak power rating handles repetitive 100 ms load dump pulses without degradation. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar unidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ30A | Lower PPP (400 W), higher VCL (48.4 V), same SMC package | Limited to lower-energy transients; not qualified to AEC-Q101 | Select when cost sensitivity outweighs automotive qualification and surge margin |
| TPSMA6L30A | Higher leakage (1 µA), lower Tj max (150 °C), identical VBR/VCL specs | Not rated for ISO 7637-2 Pulse 3a/b; suitable for non-automotive industrial use | Choose for commercial-grade designs where extended temperature range is unnecessary |
Compared with SMAJ30A and TPSMA6L30A, SM30T30AY provides superior automotive robustness through AEC-Q101 qualification, 3000 W surge capability, and 175 °C operation-making it the only choice for under-hood ECU, ADAS, and EPS applications requiring full ISO 7637-2 compliance.
Availability
SM30T30AY is available at Aetrix Electronics and suitable for engine control units, body control modules, ADAS camera systems, and electric power steering systems requiring stable component supply and full automotive qualification.
Supply support for SM30T30AY 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 innovative solutions across automotive, industrial, and power management markets.
The SM30TY series belongs to ST's automotive-grade TVS portfolio, engineered specifically to meet ISO 7637-2, ISO 10605, and AEC-Q101 requirements for next-generation vehicle electronics protection.
FAQ
What is the maximum clamping voltage for SM30T30AY under a 10/1000 µs surge?
The maximum clamping voltage (VCL) is 42.1 V at 71 A for a 10/1000 µs waveform, measured at 25 °C ambient. This value increases with junction temperature at a rate defined by αT = 9.7 × 10⁻⁴ /°C, reaching ~45.2 V at 125 °C junction temperature.
Is SM30T30AY suitable for protecting CAN FD interfaces?
Yes-its low dynamic resistance (9.7 mΩ) and fast response time (<1 ns) preserve signal edge integrity on CAN FD buses up to 5 Mbps. It must be placed at the connector interface with proper layout (short traces, ground plane) to avoid impedance discontinuities.
How does SM30T30AY differ from bidirectional variants like SM30T30CAY?
SM30T30AY is unidirectional and protects only against reverse-polarity surges on positive supply lines, while SM30T30CAY provides symmetrical clamping for AC-coupled or dual-polarity signals. The unidirectional version offers lower leakage (0.2 µA vs. 1 µA typical) and tighter VBR tolerance.
Can SM30T30AY be used in 24 V commercial truck systems?
No-it is rated for VRM = 28.9 V and intended for 12 V nominal automotive systems. For 24 V systems, select SM30T42AY (VRM = 38.1 V) or SM30T47AY (VRM = 42.4 V), both validated for ISO 7637-2 Pulse 5b load dump up to 87 V.
SM30T30AY 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):
- 26V
- Voltage - Breakdown (Min):
- 28.9V
- Voltage - Clamping (Max) @ Ipp:
- 42.1V
- Current - Peak Pulse (10/1000µs):
- 71.3A
- 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
SM30T30AY FAQ
1.How can I place an order for SM30T30AY through Aetrix?
Please submit a Request for Quotation (RFQ) for SM30T30AY 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 SM30T30AY reliable?
The price and inventory of SM30T30AY are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SM30T30AY is usually 5 days.
3.What payment methods are accepted for SM30T30AY?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM30T30AY transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SM30T30AY?
SM30T30AY orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SM30T30AY 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 SM30T30AY?
For technical support, including SM30T30AY datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM30T30AY requirements.
6.How does Aetrix verify that SM30T30AY is sourced from the original manufacturer or authorized distributors?
All SM30T30AY 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 SM30T30AY meets industry standards.
7.What is the process for return or replacement of SM30T30AY?
All SM30T30AY units undergo pre-shipment inspection (PSI). If there is an issue with SM30T30AY, 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 SM30T30AY part is unused and in its original packaging.
Return procedure for SM30T30AY:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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