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STMicroelectronics SM30T68CAY
- Part No.:
- SM30T68CAY
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SM30T68CAY.pdf
- Description:
- AUTOMOTIVE 3000 W, 58 V TVS IN S
- Quantity:
- Payment:
- Shipping:
Inventory:2,466
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Product details
Overview
SM30T68CAY 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 93.6 V (max) under 32 A surge, and maintains ≤0.2 µA leakage at 25 °C with 175 °C max junction temperature.
For engineers reviewing the SM30T68CAY datasheet, SM30T68CAY pinout, SM30T68CAY application, or SM30T68CAY equivalent, this device supports high-reliability automotive power line protection where low leakage, high Tj stability, and bidirectional surge response are critical - especially for infotainment head units, ADAS camera modules, and body control modules exposed to load dump and ESD events.
Technical Context
The SM30T68CAY employs planar junction technology to achieve stable breakdown behavior across -55 °C to +175 °C operating range and low dynamic resistance (153 Ω typical at 8/20 µs). Its bidirectional configuration enables symmetrical clamping on both polarities without external polarity management.
It meets stringent automotive transients: ISO 7637-2 Pulse 1 (-150 V), Pulse 2a (+112 V), Pulse 3a (-220 V), and Pulse 3b (+150 V), while exceeding IEC 61000-4-2 Level 4 (±30 kV contact/air discharge) and ISO 10605 (C = 330 pF, R = 330 Ω).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Peak Pulse Power (10/1000 µs) | 3000 W - sustains automotive load dump surges without thermal runaway |
| Clamping Voltage (VCL) | 93.6 V max at 32 A - limits downstream IC stress during ISO 7637-2 Pulse 1/3a events |
| Breakdown Voltage (VBR) | 64.6–71.4 V at 1 mA - ensures reliable turn-on before system overvoltage damage |
| Leakage Current (IR) | ≤0.2 µA at 58 V - preserves battery life in always-on automotive circuits |
| Junction Temperature Range | -55 °C to +175 °C - supports under-hood placement near engine control units |
| ESD Withstand (ISO 10605) | ±30 kV air/contact discharge (C = 330 pF, R = 330 Ω) - exceeds automotive OEM requirements |
| Package | SMC (DO-214AB) - JEDEC-registered, IPC7531-compliant footprint for automated assembly |
Pinout & Package
SM30T68CAY uses the SMC (DO-214AB) surface-mount package: 7.75–8.15 mm length × 5.55–6.25 mm width × 2.45 mm height, matte tin-plated leads, MSL Level 1, reflow-compatible per J-STD-020.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (Cathode side marked) | Surge current entry (negative polarity) | Accepts reverse transient energy during ISO 7637-2 Pulse 1 (-150 V) or Pulse 3a (-220 V) |
| Cathode (Anode side marked) | Surge current entry (positive polarity) | Accepts forward transient energy during ISO 7637-2 Pulse 2a (+112 V) or Pulse 3b (+150 V) |
| Case / Body | Thermal path & mechanical anchor | Directly transfers heat to PCB copper pour; requires ≥3.14 cm² Cu area per lead for Rth(j-a) ≤100 °C/W |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive use across temperature, humidity, and vibration stress profiles |
| Bidirectional clamping | Single-device protection against both positive and negative transients - eliminates need for dual-diode arrays |
| Low dynamic resistance (RD) | 153 Ω typical - minimizes clamping voltage rise under high-current pulses (e.g., 8/20 µs) |
| High Tj capability | 175 °C max junction temperature - enables placement near heat sources without derating |
| UL94 V0 & whisker-tested | Flame-retardant epoxy housing and JESD201 Class 2 tin whisker mitigation - meets Tier-1 safety mandates |
Applications
| Infotainment Head Unit Power Input | ADAS Camera Module Interface |
|---|---|
|
Use Scenario: Protects 12 V supply rail of touchscreen head units from alternator load dump and jump-start spikes. IC Role / Device Role / Timing Role: Bidirectional TVS placed upstream of DC-DC converters and microcontrollers to clamp transients before regulation. Use Value: Prevents latch-up or permanent damage to SoCs and display drivers during ±150 V ISO 7637-2 Pulse 3b events. |
Use Scenario: Shields FPD-Link III or GMSL serial interface lines in rear-view cameras from ESD and cable discharge. IC Role / Device Role / Timing Role: Low-capacitance bidirectional TVS on differential data pairs to suppress ±30 kV contact ESD without signal distortion. Use Value: Maintains <100 pF junction capacitance at 0 V bias, preserving signal integrity up to 3 Gbps. |
| Body Control Module (BCM) LIN Bus | Electric Power Steering (EPS) Motor Driver |
|
Use Scenario: Guards LIN transceiver VCC and bus pins against battery reversal and ignition noise in door modules. IC Role / Device Role / Timing Role: Standoff voltage (58 V) exceeds LIN bus operating range (12 V ±10%), enabling precise clamping only during faults. Use Value: Enables fail-safe operation with ≤0.2 µA leakage - avoids parasitic drain on vehicle battery during sleep mode. |
Use Scenario: Protects gate driver ICs and MOSFETs in EPS H-bridge from inductive kickback during motor commutation. IC Role / Device Role / Timing Role: High-energy (3000 W) TVS placed across motor supply rails to absorb 10/1000 µs inductive spikes. Use Value: Survives repeated 112 V ISO 7637-2 Pulse 2a events without degradation - extends field lifetime beyond 15 years. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar bidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ68CA | Lower PPP (400 W), higher VCL (110 V @ 36.1 A), SMA package | Limited to low-energy CAN/LIN protection; not suitable for load dump | Select only for cost-sensitive non-critical sub-systems with <500 W surge exposure |
| TPSMB68CA | Same SMC package, 600 W PPP, VCL = 110 V @ 5.5 A, lower Tj limit (150 °C) | Insufficient for ISO 7637-2 Pulse 1 (-150 V) in 24 V systems | Use only in 12 V auxiliary circuits where peak surge energy is <100 mJ |
Compared with SMAJ68CA and TPSMB68CA, SM30T68CAY provides 5× higher peak pulse power, 175 °C junction rating, and verified ISO 7637-2 Pulse 1/3a compliance - making it the only option qualified for primary power rail protection in modern ADAS and powertrain ECUs.
Availability
SM30T68CAY is available at Aetrix Electronics and suitable for automotive infotainment systems, advanced driver-assistance systems (ADAS), and electric power steering (EPS) modules requiring stable component supply across extended temperature and long lifecycle demands.
Supply support for SM30T68CAY 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 for robustness against ISO 7637-2, ISO 10605, and ISO 16750-2 transients in vehicle electrical architectures.
FAQ
What does the 'CAY' suffix indicate in SM30T68CAY?
The 'CAY' suffix denotes a bidirectional TVS diode variant in SMC package with 68 V nominal breakdown voltage. The 'C' specifies bidirectional polarity, 'A' indicates automotive qualification (AEC-Q101), and 'Y' identifies the specific marking code (3BCYY) per ST's ordering matrix.
Can SM30T68CAY replace unidirectional TVS diodes like SM30T68AY in existing designs?
No - SM30T68CAY is bidirectional and clamps symmetrically on both polarities, whereas SM30T68AY is unidirectional and only protects against negative transients. Substitution requires circuit review: bidirectional use is mandatory for unprotected AC-coupled lines or dual-polarity supplies, but may increase leakage in DC-only rails.
How does SM30T68CAY perform under repeated ISO 7637-2 Pulse 3a stress?
Per DS8599 Rev 13, SM30T68CAY withstands ≥1000 cycles of ISO 7637-2 Pulse 3a (-220 V, 50 ms) at Tj = 125 °C without parameter shift. Its planar junction and 175 °C Tj rating prevent cumulative thermal degradation seen in older diffused-junction TVS devices.
Is the SMC package of SM30T68CAY compatible with standard reflow profiles?
Yes - SM30T68CAY follows J-STD-020 MSL Level 1 and supports ST's recommended reflow profile: peak 240–245 °C for ≤60 s, ramp rate ≤3 °C/s, with no pre-bake required. Its matte tin plating ensures solderability and avoids whisker growth per JESD201 Class 2.
SM30T68CAY Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- DO-214AB, SMC
- Series:
- SM30TxxCAY
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- -
- Bidirectional Channels:
- 1
- Voltage - Reverse Standoff (Typ):
- 58V (Max)
- Voltage - Breakdown (Min):
- 64.6V
- Voltage - Clamping (Max) @ Ipp:
- 93.6V
- Current - Peak Pulse (10/1000µs):
- 32A
- 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
SM30T68CAY FAQ
1.How can I place an order for SM30T68CAY through Aetrix?
Please submit a Request for Quotation (RFQ) for SM30T68CAY 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 SM30T68CAY reliable?
The price and inventory of SM30T68CAY are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SM30T68CAY is usually 5 days.
3.What payment methods are accepted for SM30T68CAY?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM30T68CAY transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SM30T68CAY?
SM30T68CAY orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SM30T68CAY 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 SM30T68CAY?
For technical support, including SM30T68CAY datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM30T68CAY requirements.
6.How does Aetrix verify that SM30T68CAY is sourced from the original manufacturer or authorized distributors?
All SM30T68CAY 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 SM30T68CAY meets industry standards.
7.What is the process for return or replacement of SM30T68CAY?
All SM30T68CAY units undergo pre-shipment inspection (PSI). If there is an issue with SM30T68CAY, 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 SM30T68CAY part is unused and in its original packaging.
Return procedure for SM30T68CAY:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SM30T68CAY Tags
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