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STMicroelectronics SM30T26CAY
- Part No.:
- SM30T26CAY
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SM30T26CAY.pdf
- Description:
- TVS DIODE 22VWM 35.5VC SMC
- Quantity:
- Payment:
- Shipping:
Inventory:6,882
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Product details
Overview
SM30T26CAY from STMicroelectronics is a bidirectional automotive-grade transient voltage suppression (TVS) diode in SMC package, designed for ISO 7637-2 pulse protection and ISO 10605 ESD immunity in 12 V/24 V vehicle systems. It delivers 3000 W peak pulse power (10/1000 µs), clamps at 35.5 V (max) under 100 A surge, and maintains ≤0.2 µA leakage at 25 °C with 25.7 V nominal breakdown voltage.
For engineers reviewing the SM30T26CAY datasheet, SM30T26CAY pinout, SM30T26CAY application, or SM30T26CAY equivalent, this device is selected for high-reliability automotive power line protection where low leakage, 175 °C junction operation, and bidirectional surge handling per ISO 7637-2 Pulse 1/2a/3a/3b are required.
Technical Context
The SM30T26CAY uses planar silicon junction technology to achieve stable breakdown voltage drift (αT = 9.6 × 10−4/°C), low dynamic resistance (RD = 30.4 mΩ), and robust thermal performance up to Tj = 175 °C. Its bidirectional architecture enables symmetrical clamping on both polarities without external polarity constraints.
It meets IEC 61000-4-4 Level 4 (4 kV), exceeds ISO 10605 Level 4 (±30 kV air/contact discharge), and supports load dump immunity per ISO 16750-2 Test B (87 V, 150 ms/400 ms). The device is qualified to AEC-Q101 and rated for MSL Level 1 reflow compatibility.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Breakdown Voltage (VBR) | 24.4 V (min), 25.7 V (typ), 27 V (max) at IBR = 1 mA - defines precise clamping onset threshold for bidirectional overvoltage events. |
| Clamping Voltage (VCL) | 35.5 V (max) at IPP = 100 A (10/1000 µs) - ensures downstream ICs see ≤35.5 V during worst-case transients. |
| Peak Pulse Power (PPP) | 3000 W (10/1000 µs), up to 48.3 kW (8/20 µs) - sustains high-energy surges without failure in automotive load dump scenarios. |
| Leakage Current (IR) | ≤0.2 µA at VRM = 22 V and Tj = 25 °C - minimizes standby power loss and avoids false triggering in always-on circuits. |
| Junction Temperature Range | −55 °C to +175 °C - enables direct placement near hot engine control units or power converters without derating. |
| ESD Withstand (ISO 10605) | ±30 kV (air & contact discharge, C = 150 pF / R = 330 Ω) - exceeds automotive OEM requirements for infotainment and ADAS interface ports. |
| Package | SMC (DO-214AB), JEDEC registered outline - provides mechanical robustness and thermal dissipation compatible with standard FR4 PCB footprints. |
Pinout & Package
SM30T26CAY is housed in an SMC (DO-214AB) surface-mount package with two terminals: Cathode (K) and Anode (A). The bidirectional configuration means both terminals function symmetrically as current entry/exit points depending on transient polarity; no fixed cathode/anode orientation applies in circuit operation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Terminal 1 | Bidirectional Surge Terminal | Accepts transient current in either polarity; connects directly to protected line (e.g., CAN_H, LIN, battery feed). |
| Terminal 2 | Bidirectional Surge Terminal | Completes surge path to ground or return rail; requires low-inductance layout to maintain clamping integrity. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualification | Validated for automotive under-hood and chassis applications with full temperature cycling, humidity, and mechanical shock testing. |
| Low dynamic resistance (RD) | 30.4 mΩ enables tighter clamping voltage margin and reduced energy dissipation during fast 8/20 µs transients. |
| High junction temperature rating | 175 °C maximum operating temperature allows placement near power MOSFETs or DC-DC converters without thermal derating. |
| Matte tin lead finish | Complies with J-STD-002 and JESD 22-B102 E3 for solderability and whisker resistance in long-life automotive modules. |
| ISO 7637-2 compliance | Validated response to Pulse 1 (−150 V), Pulse 2a (+112 V), Pulse 3a (−220 V), and Pulse 3b (+150 V) on 12 V systems. |
Applications
| Engine Control Unit (ECU) Power Input | Body Control Module (BCM) LIN Bus |
|---|---|
|
Use Scenario: Protects 12 V supply rail of engine ECU against alternator load dump and battery reverse connection transients. IC Role / Device Role / Timing Role: Bidirectional TVS placed between battery feed and input filter capacitor to clamp surges before LDOs and microcontrollers. Use Value: Limits peak voltage to 35.5 V during 100 A transients, preventing damage to 40 V-rated input stages and ensuring ASIL-B functional safety compliance. |
Use Scenario: Shields LIN transceiver PHY layer from ESD events and coupled noise on vehicle body wiring harnesses. IC Role / Device Role / Timing Role: Placed across LIN bus lines (LIN and GND) to suppress ±30 kV contact discharge without distorting 19.2 kbps signaling. Use Value: Maintains <0.2 µA leakage to avoid bus pull-down, enabling reliable wake-up detection and meeting LIN 2.2A electrical specifications. |
| ADAS Camera Power Supply | Infotainment Head Unit USB Port |
|
Use Scenario: Guards 5 V/3.3 V camera module power rails against ISO 7637-2 Pulse 3b (+150 V) induced by nearby solenoid switching. IC Role / Device Role / Timing Role: Mounted at connector entry point to absorb fast-rising transients before DC-DC converter input capacitors. Use Value: Clamps within 1 ns response time and dissipates 3000 W peak power, preserving image sensor startup integrity and avoiding reset loops. |
Use Scenario: Provides secondary ESD protection on USB VBUS line in head unit, supplementing internal transceiver protection. IC Role / Device Role / Timing Role: Bidirectional TVS connected between VBUS and chassis ground to shunt ±30 kV discharges away from USB controller IC. Use Value: Delivers 35.5 V clamping at 100 A while maintaining <100 pF junction capacitance, preventing USB 2.0 signal integrity degradation. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar bidirectional automotive TVS applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ26CA | Lower PPP = 400 W (10/1000 µs); higher VCL = 42.1 V at 50 A; SMC package but not AEC-Q101 qualified. | Limited to non-safety-critical cabin modules; unsuitable for ECU or ADAS due to insufficient surge rating and qualification gap. | Select only for cost-sensitive, non-automotive industrial designs where 400 W peak power suffices and AEC-Q101 is not mandated. |
| TPSMD26C | PPP = 3000 W (10/1000 µs); VCL = 35.5 V at 100 A; AEC-Q101 qualified; but higher leakage (1 µA) and lower Tj max = 150 °C. | Acceptable for BCM or lighting control, but marginal for under-hood ECUs requiring 175 °C operation and ultra-low leakage. | Prefer SM30T26CAY when junction temperature exceeds 150 °C or leakage must stay below 0.5 µA in always-on monitoring circuits. |
Compared with SMAJ26CA and TPSMD26C, SM30T26CAY uniquely combines AEC-Q101 qualification, 175 °C operation, 0.2 µA leakage, and validated ISO 7637-2 Pulse 1–3b response-making it the only choice for ASIL-B power rail protection in modern engine and ADAS domains.
Availability
SM30T26CAY is available at Aetrix Electronics and suitable for automotive engine control units, body control modules, ADAS camera systems, and infotainment head units requiring stable component supply across multi-year production cycles.
Supply support for SM30T26CAY 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 silicon solutions for automotive, industrial, and consumer markets since 1987.
The SM30Txx series belongs to ST's automotive-grade transient protection product line, engineered specifically to meet stringent ISO 7637-2, ISO 10605, and AEC-Q101 requirements for next-generation vehicle electronics.
FAQ
Is SM30T26CAY unidirectional or bidirectional?
SM30T26CAY is a bidirectional TVS diode, indicated by the "C" in its part number. It provides symmetrical clamping for both positive and negative transients without requiring polarity-specific layout, making it ideal for AC-coupled lines like LIN, CAN, or differential power rails.
What is the maximum clamping voltage at 100 A for SM30T26CAY?
The maximum clamping voltage (VCL) for SM30T26CAY is 35.5 V at 100 A for a 10/1000 µs waveform, as specified in Table 2 of DS8599 Rev 13. This value is measured at Tamb = 25 °C and remains valid up to Tj = 125 °C with linear temperature coefficient compensation.
Does SM30T26CAY require heatsinking on standard FR4 PCB?
No additional heatsink is required. With Rth(j-a) ≈ 100 °C/W on a recommended footprint (5.11 mm × 8.19 mm copper area), the device safely handles 3000 W pulses for short durations. Thermal impedance drops to ~30 °C/W with 3 cm² copper per terminal, sufficient for continuous operation at Tj ≤ 175 °C.
Can SM30T26CAY replace SM30T26AY in a design?
SM30T26CAY (bidirectional) and SM30T26AY (unidirectional) are not functionally interchangeable. Substituting one for the other alters surge path symmetry and may cause improper clamping on reverse-polarity transients. Use SM30T26CAY only where bidirectional protection is explicitly required, such as across differential buses or floating supplies.
SM30T26CAY 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):
- 22V
- Voltage - Breakdown (Min):
- 24.4V
- Voltage - Clamping (Max) @ Ipp:
- 35.5V
- Current - Peak Pulse (10/1000µs):
- 84.5A
- 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
SM30T26CAY FAQ
1.How can I place an order for SM30T26CAY through Aetrix?
Please submit a Request for Quotation (RFQ) for SM30T26CAY 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 SM30T26CAY reliable?
The price and inventory of SM30T26CAY are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SM30T26CAY is usually 5 days.
3.What payment methods are accepted for SM30T26CAY?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM30T26CAY transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SM30T26CAY?
SM30T26CAY orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SM30T26CAY 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 SM30T26CAY?
For technical support, including SM30T26CAY datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM30T26CAY requirements.
6.How does Aetrix verify that SM30T26CAY is sourced from the original manufacturer or authorized distributors?
All SM30T26CAY 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 SM30T26CAY meets industry standards.
7.What is the process for return or replacement of SM30T26CAY?
All SM30T26CAY units undergo pre-shipment inspection (PSI). If there is an issue with SM30T26CAY, 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 SM30T26CAY part is unused and in its original packaging.
Return procedure for SM30T26CAY:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SM30T26CAY Tags
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