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STMicroelectronics SM30T35CAY
- Part No.:
- SM30T35CAY
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SM30T35CAY.pdf
- Description:
- TVS DIODE 30VWM 48.4VC SMC
- Quantity:
- Payment:
- Shipping:
Inventory:419
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Product details
Overview
SM30T35CAY from STMicroelectronics is a bidirectional automotive-grade transient voltage suppression (TVS) diode in SMC package, designed for ISO 7637-2 pulse protection in 12 V/24 V vehicle systems. It delivers 3000 W peak pulse power (10/1000 µs), clamps at 48.4 V (max) under 185 A surge, and operates up to 175 °C junction temperature - deployed in engine control units, body control modules, and infotainment power rails.
For engineers reviewing the SM30T35CAY datasheet, SM30T35CAY pinout, SM30T35CAY application, or SM30T35CAY equivalent, key selection criteria include bidirectional clamping behavior, 35 V nominal breakdown voltage, low leakage (0.2 µA at 25 °C), AEC-Q101 qualification, and compliance with ISO 10605 ±30 kV ESD and ISO 7637-2 Pulse 1/2a/3a/3b.
Technical Context
This TVS diode uses planar silicon technology to achieve stable high-temperature operation (Tj up to 175 °C) and ultra-low leakage current (0.2 µA at VRM = 30 V). Its bidirectional architecture enables symmetrical clamping for both positive and negative transients without polarity dependency.
It meets stringent automotive surge immunity standards: ISO 7637-2 Pulse 1 (−150 V), Pulse 2a (+112 V), Pulse 3a (−220 V), and Pulse 3b (+150 V), while maintaining dynamic resistance of 48.2 mΩ and clamping voltage ≤48.4 V at 185 A (10/1000 µs).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Breakdown Voltage (VBR) | 33.3–36.9 V at 1 mA - defines precise conduction onset for overvoltage triggering |
| Clamping Voltage (VCL) | 48.4 V max at 185 A (10/1000 µs) - ensures downstream ICs see safe voltage during surge |
| Peak Pulse Power | 3000 W (10/1000 µs) - sustains high-energy transients common in automotive load dump and switching events |
| Leakage Current (IRM) | 0.2 µA at VRM = 30 V, 25 °C - minimizes standby power loss and signal integrity impact |
| Junction Temperature Range | −55 to +175 °C - supports under-hood deployment in extreme thermal environments |
| ESD Withstand | ±30 kV (air & contact, ISO 10605, C = 330 pF/R = 330 Ω) - exceeds automotive ESD immunity requirements |
| Package | SMC (DO-214AB) - JEDEC-registered surface-mount outline with 7.75–8.15 mm width and 5.55–6.25 mm length |
Pinout & Package
The SM30T35CAY is housed in an SMC (DO-214AB) package with two terminals: Cathode (K) and Anode (A), arranged in a single-row, gull-wing lead configuration. The device is bidirectional, meaning both terminals function symmetrically as clamping paths for positive and negative transients.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| K (Cathode) | Surge current return path | Primary terminal for transient energy shunting to ground or rail; bidirectional symmetry eliminates polarity constraints |
| A (Anode) | Surge current input path | Accepts transient voltage from protected line; functions identically to K under reverse polarity events |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive use across temperature, humidity, and mechanical stress cycles per JESD22 standards |
| Bidirectional clamping | Enables single-device protection of AC-coupled or floating lines without external polarity management |
| Low dynamic resistance (RD) | 48.2 mΩ - reduces clamping voltage rise under high-current surges, improving protection margin |
| High-temperature reliability | Rated for continuous operation at Tj = 175 °C - suitable for placement near heat-generating ECUs |
| Matte tin lead finish | Complies with J-STD-002 and JESD 22-B102 E3 - ensures solderability and whisker resistance |
Applications
| Engine Control Unit (ECU) Power Input | Body Control Module (BCM) CAN Bus Lines |
|---|---|
Use Scenario: Protection against load dump pulses (ISO 7637-2 Pulse 5b) and alternator-induced spikes on 12 V supply rails. IC Role / Device Role / Timing Role: Bidirectional TVS placed between battery input and DC-DC converter input stage. Use Value: Clamps transients to ≤48.4 V within 10/1000 µs, preventing damage to LDOs and microcontrollers rated for 40 V absolute maximum. | Use Scenario: ESD and coupled noise suppression on differential CAN H/L lines exposed to door harnesses and seat motors. IC Role / Device Role / Timing Role: Low-capacitance bidirectional TVS mounted directly at connector entry point. Use Value: Withstands ±30 kV contact discharge (ISO 10605) while adding <100 pF capacitance, preserving CAN signal integrity up to 1 Mbps. |
| Infotainment Head Unit Power Supply | ADAS Camera Module Interface |
Use Scenario: Surge protection for USB-C PD and display power inputs subjected to hot-swap and cable coupling events. IC Role / Device Role / Timing Role: Primary front-end TVS on 5 V/12 V rail before PMIC and SoC power domains. Use Value: 3000 W peak power rating handles repeated 10/1000 µs surges without degradation, supporting 15-year automotive lifecycle. | Use Scenario: Transient suppression on FAKRA or HSD camera links exposed to chassis-ground bounce and ignition noise. IC Role / Device Role / Timing Role: Bidirectional TVS integrated into camera PCB's I/O filter network adjacent to connector. Use Value: 0.2 µA leakage at 30 V prevents bias drift in analog video amplifiers and maintains low-noise performance in image signal chain. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar bidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ33CA | Lower peak power (400 W), higher clamping voltage (53.3 V at 7.5 A), SMA package | Not AEC-Q101 qualified; limited to non-automotive industrial use | Select only for cost-sensitive, non-automotive designs with lower surge exposure |
| TPSMD33C | Same SMC package, 33 V VBR, but unidirectional; requires dual-device layout for bidirectional coverage | Lacks inherent symmetry - increases BOM count and PCB area vs. single SM30T35CAY | Use only when system-level polarity is fixed and space allows discrete directional protection |
Compared with SMAJ33CA and TPSMD33C, SM30T35CAY uniquely combines AEC-Q101 qualification, 3000 W surge capability, true bidirectionality in one SMC device, and 175 °C operation - making it the only drop-in solution for high-reliability automotive power rail protection where thermal margin and standard compliance are mandatory.
Availability
SM30T35CAY is available at Aetrix Electronics and suitable for engine control units, body control modules, and infotainment head units requiring stable component supply across extended automotive production lifecycles.
Supply support for SM30T35CAY 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 automotive, industrial, and power management solutions since 1987.
The SM30Txx series belongs to ST's automotive-grade TVS portfolio, engineered specifically to meet ISO 7637-2, ISO 10605, and AEC-Q101 requirements for robust, high-temperature transient suppression in modern vehicle electronics.
FAQ
What is the difference between SM30T35AY and SM30T35CAY?
SM30T35AY is unidirectional (anode-to-cathode conduction only), while SM30T35CAY is bidirectional - conducting equally in both polarities. This makes SM30T35CAY suitable for protecting AC-coupled or floating signal lines like CAN or LIN without polarity concerns, whereas SM30T35AY requires correct orientation relative to ground.
Does SM30T35CAY require heatsinking in typical automotive applications?
No additional heatsink is required. The SMC package provides sufficient thermal dissipation for transient events, and its 175 °C maximum junction temperature rating accommodates ambient under-hood temperatures up to 125 °C with standard PCB copper area (≥3 cm² per pad), as validated in Figure 12 of DS8599.
Can SM30T35CAY be used in 24 V commercial vehicle systems?
Yes - its 35 V nominal breakdown and 48.4 V clamping voltage provide adequate margin above 24 V nominal systems (including 28 V alternator regulation), and it meets ISO 7637-2 Pulse 1 (−150 V) and Pulse 3b (+150 V) requirements applicable to heavy-duty vehicles.
How does the dynamic resistance (RD = 48.2 mΩ) affect clamping performance?
Dynamic resistance determines voltage rise under surge current: VCL = VBR + (RD × IPP). At 185 A, RD contributes ~8.8 V to clamping - keeping total VCL ≤48.4 V. Lower RD improves protection margin for downstream 40 V-rated ICs, especially during fast-rising 8/20 µs transients.
SM30T35CAY 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:
- -
- Bidirectional Channels:
- 1
- 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
SM30T35CAY FAQ
1.How can I place an order for SM30T35CAY through Aetrix?
Please submit a Request for Quotation (RFQ) for SM30T35CAY 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 SM30T35CAY reliable?
The price and inventory of SM30T35CAY are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SM30T35CAY is usually 5 days.
3.What payment methods are accepted for SM30T35CAY?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM30T35CAY transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SM30T35CAY?
SM30T35CAY orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SM30T35CAY 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 SM30T35CAY?
For technical support, including SM30T35CAY datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM30T35CAY requirements.
6.How does Aetrix verify that SM30T35CAY is sourced from the original manufacturer or authorized distributors?
All SM30T35CAY 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 SM30T35CAY meets industry standards.
7.What is the process for return or replacement of SM30T35CAY?
All SM30T35CAY units undergo pre-shipment inspection (PSI). If there is an issue with SM30T35CAY, 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 SM30T35CAY part is unused and in its original packaging.
Return procedure for SM30T35CAY:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SM30T35CAY Tags
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ESD9B5.0ST5G
onsemi
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DESD3V3E1BL-7B
Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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onsemi
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Diodes Incorporated
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Diodes Incorporated
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Nexperia USA Inc.
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Toshiba Semiconductor and Storage
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Diodes Incorporated
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