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STMicroelectronics SM30T39CAY
- Part No.:
- SM30T39CAY
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SM30T39CAY.pdf
- Description:
- TVS DIODE 33VWM 53.3VC SMC
- Quantity:
- Payment:
- Shipping:
Inventory:2,424
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Product details
Overview
SM30T39CAY from STMicroelectronics is a bidirectional automotive-grade transient voltage suppression (TVS) diode in SMC package, designed for ISO 7637-2 pulse protection and IEC 61000-4-2/ISO 10605 ESD hardening of 12 V/24 V vehicle power nets. It delivers 3000 W peak pulse power (10/1000 µs), clamps at 53.3 V (max) under 227 A surge, and operates up to 175 °C junction temperature - enabling robust front-end protection in engine control units, body control modules, and ADAS sensor interfaces.
For engineers reviewing the SM30T39CAY datasheet, SM30T39CAY pinout, SM30T39CAY application, or SM30T39CAY equivalent, key selection criteria include bidirectional clamping capability, low leakage (0.2 µA at 25 °C), AEC-Q101 qualification, ISO 7637-2 Pulse 1/2a/3a/3b compliance, and SMC package thermal performance on FR4 PCBs.
Technical Context
This TVS diode uses planar silicon technology to achieve stable breakdown voltage (VBR = 36.7–40.5 V), low dynamic resistance (RD = 55.5 Ω), and minimal capacitance (<100 pF at 1 VR) - critical for preserving signal integrity in high-speed CAN/LIN bus nodes while suppressing transients. Its bidirectional configuration enables symmetrical clamping across battery rails without polarity dependency.
The device meets stringent automotive surge immunity requirements: ±30 kV ESD (IEC 61000-4-2, C = 150 pF/R = 330 Ω), ±30 kV (C = 330 pF/R = 330 Ω), and ISO 7637-2 pulses including Pulse 1 (−150 V), Pulse 2a (+112 V), Pulse 3a (−220 V), and Pulse 3b (+150 V) - all validated at Tj = 175 °C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Peak Pulse Power (10/1000 µs) | 3000 W - sustains automotive load dump and alternator switching surges without degradation |
| Clamping Voltage (VCL) | 53.3 V max at 227 A - limits downstream IC stress below 5.5 V rail tolerance thresholds |
| Breakdown Voltage (VBR) | 36.7–40.5 V at 1 mA - ensures reliable triggering before sensitive 42 V-rated components fail |
| Leakage Current (IR) | 0.2 µA at 25 °C - prevents battery drain in always-on vehicle modules |
| Junction Temperature Range | −55 to +175 °C - supports under-hood placement near engines and power electronics |
| ESD Withstand (IEC 61000-4-2) | ±30 kV contact/air discharge - exceeds automotive OEM Level 4 requirements |
| Package | SMC (DO-214AB) - JEDEC-registered outline with 7.75–8.15 mm width for high-current PCB routing |
Pinout & Package
SM30T39CAY is a 2-terminal bidirectional TVS diode in SMC (DO-214AB) package. The cathode/anode terminals are non-polarized; both leads serve as symmetrical surge current paths during positive or negative transients.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (Lead 1) | Surge current entry (negative transient) | Carries full reverse surge current during ISO 7637-2 Pulse 1 (−150 V) and Pulse 3a (−220 V) |
| Cathode (Lead 2) | Surge current entry (positive transient) | Carries full forward surge current during ISO 7637-2 Pulse 2a (+112 V) and Pulse 3b (+150 V) |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive under-hood use with 1000-cycle temperature cycling and 1000-hr high-temp operating life |
| Bidirectional clamping | Enables single-device protection of dual-polarity supply rails (e.g., CAN H/L, LIN bus, sensor VCC/GND) |
| Low dynamic resistance (RD) | 55.5 Ω - minimizes clamping voltage rise under high di/dt surges (e.g., 8/20 µs lightning-like events) |
| Matte tin lead finish | Complies with J-STD-002 and JESD 22-B102 E3 - ensures solderability and whisker resistance in reflow assembly |
| JEDEC-registered SMC footprint | Matches IPC-7531 standard - guarantees mechanical compatibility with automated pick-and-place and AOI inspection |
Applications
| Engine Control Unit (ECU) Power Input | ADAS Camera Module Interface |
|---|---|
Use Scenario: Protection of 12 V main power input against load dump (ISO 7637-2 Pulse 5b) and alternator ripple-induced transients. IC Role / Device Role / Timing Role: Primary overvoltage clamp upstream of DC/DC converters and microcontroller power supplies. Use Value: Limits VIN to ≤53.3 V during 150 ms load dump events, preventing brownout reset and MOSFET gate oxide failure in PMICs. |
Use Scenario: ESD and fast transient protection on FAKRA coaxial video input lines and GMSL serial links. IC Role / Device Role / Timing Role: Low-capacitance bidirectional shunt clamp on differential analog/video signal pairs. Use Value: Maintains <100 pF capacitance at 1 V bias to avoid signal rise-time degradation while passing ±30 kV IEC 61000-4-2 ESD. |
| Body Control Module (BCM) LIN Bus | Electric Power Steering (EPS) Motor Driver |
Use Scenario: Transient suppression on LIN transceiver VCC and bus line against battery disconnection spikes and relay bounce. IC Role / Device Role / Timing Role: Secondary protection stage after fuse, placed adjacent to LIN PHY IC. Use Value: Clamps ISO 7637-2 Pulse 2a (+112 V) within 1 ns to protect 5 V LDO regulators and LIN driver inputs. |
Use Scenario: Surge hardening of 24 V motor phase drive inputs against inductive kickback and ground bounce. IC Role / Device Role / Timing Role: High-energy clamping element parallel to H-bridge MOSFETs and gate drivers. Use Value: Absorbs 3000 W (10/1000 µs) without thermal runaway, enabling 175 °C operation near motor windings. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar bidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ39CA | Lower peak power (400 W), higher VCL (67.8 V at 5.9 A), SMA package | Not suitable for ISO 7637-2 Pulse 1 (−150 V) or Pulse 3a (−220 V) due to insufficient energy rating | Select only for low-energy consumer-grade 12 V circuits where AEC-Q101 is not required. |
| SMBJ39CA | 600 W peak power, same VBR range, SMB package, 10× lower surge current rating (64 A) | Limited to sub-systems with localized ESD-only threats (e.g., infotainment USB ports), not main power rails | Use when board space is constrained and surge exposure is limited to IEC 61000-4-2 only. |
Compared with SMAJ39CA and SMBJ39CA, SM30T39CAY provides 5× higher peak power and 3.5× higher surge current handling in an AEC-Q101-qualified SMC package - making it the only option capable of meeting full ISO 7637-2 system-level immunity requirements in modern automotive ECUs.
Availability
SM30T39CAY is available at Aetrix Electronics and suitable for engine control units, ADAS camera modules, body control modules, and electric power steering systems requiring stable component supply across multi-year automotive production cycles.
Supply support for SM30T39CAY 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, specializing in automotive, industrial, and power management ICs with vertical manufacturing and AEC-Q100/101 validation infrastructure.
SM30T39CAY belongs to the SM30TY series - a family of planar TVS diodes engineered specifically for automotive power net hardening, combining high-temperature reliability, low leakage, and ISO 7637-2/10605 compliance in JEDEC-standard packages.
FAQ
What is the maximum clamping voltage of SM30T39CAY at 227 A?
The maximum clamping voltage (VCL) is 53.3 V at 227 A for a 10/1000 µs waveform, measured at Tj = 25 °C per Table 2 of DS8599 Rev 13. This value increases linearly with junction temperature using αT = 10 × 10−4/°C, reaching ~57.5 V at 175 °C.
Is SM30T39CAY unidirectional or bidirectional?
SM30T39CAY is a bidirectional TVS diode, indicated by the "CAY" suffix per ST's marking table (3BAPY). It provides symmetrical clamping for both positive and negative transients, unlike "AY"-suffixed unidirectional variants such as SM30T39AY.
Does SM30T39CAY meet AEC-Q101 requirements?
Yes - SM30T39CAY is explicitly AEC-Q101 qualified per its features list and DS8599 documentation. It passes stress tests including temperature cycling, high-temperature operating life, and unbiased highly accelerated stress testing (uHAST) per AEC-Q101-004.
What is the thermal resistance junction-to-ambient for SM30T39CAY on standard FR4?
On a recommended footprint (5.11 mm × 8.19 mm copper pad per Figure 24), Rth(j-a) is 120 °C/W for a single pulse, dropping to ~40 °C/W with 4 cm² total copper area per Figure 12. This enables sustained 175 °C operation under pulsed conditions without heatsinking.
SM30T39CAY 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):
- 33V
- Voltage - Breakdown (Min):
- 36.7V
- Voltage - Clamping (Max) @ Ipp:
- 53.3V
- Current - Peak Pulse (10/1000µs):
- 56.3A
- 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
SM30T39CAY FAQ
1.How can I place an order for SM30T39CAY through Aetrix?
Please submit a Request for Quotation (RFQ) for SM30T39CAY 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 SM30T39CAY reliable?
The price and inventory of SM30T39CAY are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SM30T39CAY is usually 5 days.
3.What payment methods are accepted for SM30T39CAY?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM30T39CAY transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SM30T39CAY?
SM30T39CAY orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SM30T39CAY 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 SM30T39CAY?
For technical support, including SM30T39CAY datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM30T39CAY requirements.
6.How does Aetrix verify that SM30T39CAY is sourced from the original manufacturer or authorized distributors?
All SM30T39CAY 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 SM30T39CAY meets industry standards.
7.What is the process for return or replacement of SM30T39CAY?
All SM30T39CAY units undergo pre-shipment inspection (PSI). If there is an issue with SM30T39CAY, 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 SM30T39CAY part is unused and in its original packaging.
Return procedure for SM30T39CAY:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SM30T39CAY Tags
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