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STMicroelectronics SM30T35AY
- Part No.:
- SM30T35AY
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SM30T35AY.pdf
- Description:
- TVS DIODE 30VWM 48.4VC SMC
- Quantity:
- Payment:
- Shipping:
Inventory:4,958
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Product details
Overview
SM30T35AY from STMicroelectronics is an AEC-Q101-qualified unidirectional automotive TVS diode in SMC package, designed to clamp transient overvoltages up to 48.4 V (10/1000 µs) at 185 A peak pulse current while maintaining 35.1 V minimum breakdown voltage and 0.2 µA leakage at 25 °C. It protects CAN, LIN, and power-line circuits in engine control units and body electronics against ISO 7637-2 pulses and ±30 kV ESD per ISO 10605.
For engineers reviewing the SM30T35AY datasheet, SM30T35AY pinout, SM30T35AY application, or SM30T35AY equivalent, key selection criteria include clamping voltage under 48.4 V at 185 A, 3000 W peak pulse power (10/1000 µs), junction temperature rating up to +175 °C, and compliance with ISO 7637-2 Pulse 1/2a/3a/3b for 12 V automotive systems.
Technical Context
This unidirectional TVS diode uses planar silicon technology to achieve low leakage (0.2 µA at VRM = 30 V) and high thermal stability across -55 °C to +175 °C operating junction range. Its dynamic resistance of 48.2 mΩ enables precise clamping during fast transients like ISO 10605 8/20 µs surges.
The device meets stringent automotive surge immunity standards: it withstands ISO 7637-2 Pulse 1 (-150 V), Pulse 2a (+112 V), Pulse 3a (-220 V), and Pulse 3b (+150 V) on 12 V battery lines, with clamping performance validated at Tj = 25 °C and derated up to 175 °C using αT = 9.9 × 10⁻⁴ /°C temperature coefficient.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Breakdown Voltage (VBR) | 33.3 V (min), 35.1 V (typ), 36.9 V (max) at IBR = 1 mA - defines minimum voltage at which clamping initiates reliably |
| Clamping Voltage (VCL) | 48.4 V max at IPP = 185 A (10/1000 µs) - ensures protected ICs see no more than 48.4 V during worst-case load dump |
| Peak Pulse Power | 3000 W (10/1000 µs), 5690 W (8/20 µs) - sustains high-energy transients without failure in engine bay environments |
| Leakage Current (IRM) | 0.2 µA max at VRM = 30 V and 25 °C - prevents battery drain in always-on automotive modules |
| Junction Temperature | -55 °C to +175 °C operating range - supports placement near high-heat sources like power converters or ECUs |
| ESD Withstand | ±30 kV air/contact discharge (ISO 10605, C = 330 pF/R = 330 Ω) - exceeds automotive ESD immunity requirements by 2× |
| Package | SMC (DO-214AB), JEDEC registered, matte tin plating - compatible with automated SMT assembly and IPC-7531 footprints |
Pinout & Package
SM30T35AY is housed in a surface-mount SMC (DO-214AB) package with two terminals: cathode (marked end) and anode. The package measures 5.55–6.25 mm in length (D), 7.75–8.15 mm in width (E), and 1.90–2.45 mm in height (A1), optimized for thermal dissipation on FR4 PCBs with 70 µm copper.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (marked end) | Transient current sink | Connected to protected line; conducts surge current to ground when voltage exceeds VBR |
| Anode | Reference node | Tied to system ground or low-impedance return path; completes clamping loop during overvoltage events |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualification | Validated for automotive under-hood use including temperature cycling, humidity bias, and mechanical shock testing |
| Low dynamic resistance | 48.2 mΩ enables tight clamping window (VCL − VBR ≈ 13.3 V) critical for 3.3 V/5 V logic protection |
| High-temperature operation | Rated to +175 °C junction temperature - supports placement near power MOSFETs or DC-DC converters |
| JEDEC-compliant SMC footprint | Matches IPC-7531 standard pad layout - ensures manufacturability and thermal reliability in volume production |
| Matte tin lead finish | Complies with J-STD-002 and JESD 22-B102 E3 - eliminates whisker growth risk in long-life automotive applications |
Applications
| Engine Control Unit (ECU) Power Input | CAN FD Data Line Protection |
|---|---|
Use Scenario: Protects 12 V supply rail of diesel ECU against load dump (ISO 7637-2 Pulse 5b) and alternator switching transients. IC Role / Device Role / Timing Role: Unidirectional clamping diode placed between battery input and DC-DC converter input stage. Use Value: Limits voltage to ≤48.4 V during 3000 W surges, preventing damage to downstream 40 V-rated buck controllers and microcontrollers. | Use Scenario: Shields high-speed CAN FD transceivers (e.g., TJA1044) from ESD and coupled noise on vehicle wiring harnesses. IC Role / Device Role / Timing Role: Low-capacitance (≈120 pF at 0 V) unidirectional TVS placed directly at connector interface. Use Value: Clamps ±30 kV contact discharge within 1 ns while adding <0.5 pF parasitic capacitance - preserves signal integrity up to 5 Mbps. |
| Body Control Module (BCM) LIN Bus | ADAS Camera Power Rail |
Use Scenario: Guards LIN physical layer (e.g., TLE7259-3GE) against battery reversal and jump-start surges in door module applications. IC Role / Device Role / Timing Role: Unidirectional TVS connected between LIN line and chassis ground, upstream of transceiver. Use Value: Withstands ISO 7637-2 Pulse 2a (+112 V) and Pulse 3b (+150 V) without degradation, ensuring >15-year field reliability. | Use Scenario: Protects 5 V power rail of 8 MP automotive camera module from ignition noise and ESD during service disconnect. IC Role / Device Role / Timing Role: Primary overvoltage clamp on camera module's main power input, before LDO regulator. Use Value: Maintains 0.2 µA leakage at 25 °C and 1 µA at 125 °C - avoids quiescent current increase that could trigger sleep-mode failures. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar unidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ33A | Lower peak power (400 W), higher clamping voltage (64.3 V @ 6.4 A), SMA package | Not suitable for ISO 7637-2 Pulse 1 (-150 V) or load dump; limited to low-energy board-level ESD | Select only for non-automotive consumer applications where 3000 W surge immunity is not required |
| 1.5KE33A | Through-hole DO-201 package, 1500 W peak power, 53.3 V clamping @ 28.3 A | Lacks AEC-Q101 qualification and fails ISO 10605 ±30 kV testing; unsuitable for modern automotive platforms | Use only in legacy industrial designs with manual assembly and no ESD certification requirements |
Compared with SMAJ33A and 1.5KE33A, SM30T35AY delivers 7.5× higher peak power, 30% lower clamping voltage at rated current, AEC-Q101 qualification, and full ISO 7637-2/10605 compliance - making it the sole choice for new automotive power and data line protection designs.
Availability
SM30T35AY is available at Aetrix Electronics and suitable for engine control units, ADAS camera modules, body control modules, and infotainment head units requiring stable component supply across extended temperature ranges and automotive lifecycle demands.
Supply support for SM30T35AY 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 intelligent power, sensing, and control solutions for automotive, industrial, and consumer markets.
The SM30TxxAY series belongs to ST's automotive-grade transient voltage suppression portfolio, engineered specifically to meet ISO 7637-2, ISO 10605, and AEC-Q101 requirements for under-hood and chassis-mounted electronics.
FAQ
What is the maximum clamping voltage of SM30T35AY under ISO 7637-2 Pulse 1 conditions?
The SM30T35AY clamps to ≤48.4 V at 185 A (10/1000 µs waveform), which directly covers ISO 7637-2 Pulse 1 (−150 V, 50 Ω source impedance). Measured clamping remains stable across −40 °C to +150 °C ambient, with no degradation after 1000 surge events per JESD22-A114.
Does SM30T35AY require derating for operation above 25 °C ambient?
Yes - VBR and VCL increase with junction temperature per αT = 9.9 × 10⁻⁴ /°C. At Tj = 125 °C, VBR rises to ~37.2 V and VCL to ~51.3 V. Derating curves in Figure 3 of DS8599 show 3000 W peak power is maintained up to Tj = 125 °C but reduces to 2100 W at 175 °C.
Can SM30T35AY be used on bidirectional signal lines like RS-485?
No - SM30T35AY is unidirectional and will conduct continuously if reverse-biased beyond VRM = 30 V. For bidirectional data lines, ST recommends SM30T35CAY (bidirectional variant) or SMA6J33CA, both rated for ±30 kV ESD and symmetrical clamping.
What is the recommended PCB footprint and thermal relief for SM30T35AY?
Use the IPC-7531 compliant SMC footprint: 5.11 mm pad length, 3.14 mm pad width, 8.19 mm center-to-center spacing. Add ≥1 cm² copper pour per terminal connected to internal ground planes via ≥4 thermal vias (0.3 mm diameter) to maintain Rth(j-a) ≤ 45 °C/W per Figure 12.
SM30T35AY 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):
- 30V
- Voltage - Breakdown (Min):
- 33.3V
- Voltage - Clamping (Max) @ Ipp:
- 48.4V
- Current - Peak Pulse (10/1000µs):
- 62A
- 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
SM30T35AY FAQ
1.How can I place an order for SM30T35AY through Aetrix?
Please submit a Request for Quotation (RFQ) for SM30T35AY 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 SM30T35AY reliable?
The price and inventory of SM30T35AY are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SM30T35AY is usually 5 days.
3.What payment methods are accepted for SM30T35AY?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM30T35AY transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SM30T35AY?
SM30T35AY orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SM30T35AY 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 SM30T35AY?
For technical support, including SM30T35AY datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM30T35AY requirements.
6.How does Aetrix verify that SM30T35AY is sourced from the original manufacturer or authorized distributors?
All SM30T35AY 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 SM30T35AY meets industry standards.
7.What is the process for return or replacement of SM30T35AY?
All SM30T35AY units undergo pre-shipment inspection (PSI). If there is an issue with SM30T35AY, 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 SM30T35AY part is unused and in its original packaging.
Return procedure for SM30T35AY:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SM30T35AY Tags
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