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STMicroelectronics SM30T33CAY
- Part No.:
- SM30T33CAY
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SM30T33CAY.pdf
- Description:
- TVS DIODE 28VWM 45.4VC SMC
- Quantity:
- Payment:
- Shipping:
Inventory:4,637
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Product details
Overview
SM30T33CAY 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 45.4 V (max) under 168 A surge, and maintains ≤0.2 µA leakage at 25 °C - enabling robust ESD and load-dump protection in engine control units and body electronics.
For engineers reviewing the SM30T33CAY datasheet, SM30T33CAY pinout, SM30T33CAY application, or SM30T33CAY equivalent, key selection criteria include bidirectional clamping voltage (VCL = 45.4 V), junction temperature rating (Tj = 175 °C), ISO 10605 ESD immunity (±30 kV), and SMC package compatibility with high-reliability automotive PCB layouts.
Technical Context
This TVS diode uses planar silicon technology to achieve low dynamic resistance (RD = 9.8 mΩ) and stable clamping across temperature (αT = 10 × 10−4/°C). Its bidirectional architecture enables symmetrical surge suppression on differential or floating signal lines without polarity constraints.
It meets AEC-Q101 qualification and supports full ISO 7637-2 compliance: Pulse 1 (−150 V), Pulse 2a (+112 V), Pulse 3a (−220 V), and Pulse 3b (+150 V), with junction temperature operation from −55 °C to +175 °C for under-hood deployment.
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 (at IPP = 168 A) | 45.4 V max - limits downstream IC voltage stress during ISO 7637-2 Pulse 3b |
| Breakdown voltage VBR | 31.1–34.3 V (min–max at 25 °C) - ensures reliable triggering before system overvoltage damage |
| Leakage current IR | ≤0.2 µA at VRM = 30 V - prevents battery drain in always-on automotive modules |
| Junction temperature range | −55 °C to +175 °C - qualified for under-hood ECU and transmission control applications |
| ESD immunity (ISO 10605) | ±30 kV (air & contact discharge, C = 150/330 pF) - exceeds automotive infotainment and sensor interface requirements |
| Package | SMC (DO-214AB) - JEDEC-registered, IPC7531-compliant footprint for automated assembly and thermal reliability |
Pinout & Package
SM30T33CAY is housed in an SMC (DO-214AB) surface-mount package with two terminals: Cathode (K) and Anode (A). The bidirectional configuration means both terminals are functionally symmetric - no polarity-dependent mounting required.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| K (Cathode) | Surge current return path | Terminal where transient current flows into device during positive transients; tied to protected line |
| A (Anode) | Surge current return path | Terminal where transient current flows into device during negative transients; tied to protected line |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive use per stress test conditions including temperature cycling, HTRB, and mechanical shock |
| Bidirectional clamping | Enables single-device protection of AC-coupled or floating bus lines (e.g., LIN, CAN FD stubs, sensor bridges) |
| Low dynamic resistance (RD) | 9.8 mΩ - minimizes clamping voltage rise under high-current pulses (e.g., ISO 7637-2 Pulse 1) |
| High Tj max (175 °C) | Supports placement near heat sources (e.g., power converters, motor drivers) without derating |
| Matte tin lead finish | Complies with J-STD-002 and JESD 22-B102 E3 - ensures solderability and whisker resistance in long-life automotive modules |
Applications
| Engine Control Unit (ECU) | Body Control Module (BCM) |
|---|---|
|
Use Scenario: Protecting 12 V supply input against load dump (ISO 7637-2 Pulse 5b) and alternator switching transients. IC Role / Device Role / Timing Role: Primary overvoltage clamp placed upstream of DC-DC converters and microcontrollers. Use Value: Clamps to 45.4 V at 168 A, preventing >50 V stress on 48 V-tolerant LDOs and MCU I/O rails. |
Use Scenario: Safeguarding LIN bus transceivers from ESD events and battery reverse connection transients. IC Role / Device Role / Timing Role: Bidirectional line protector on LIN data line (pin 1.5), referenced to local ground. Use Value: Withstands ±30 kV contact discharge while adding <100 pF capacitance at 1 V bias - preserving 20 kbps LIN signal integrity. |
| Advanced Driver Assistance Systems (ADAS) Camera Module | Electric Power Steering (EPS) Motor Driver |
|
Use Scenario: Shielding FPD-Link III serializer inputs from cable discharge events during vehicle assembly and service. IC Role / Device Role / Timing Role: Low-leakage (0.2 µA) TVS on high-impedance video input pins, placed adjacent to connector. Use Value: Prevents false triggers and pixel corruption by limiting ESD-induced voltage overshoot to <46 V during ±30 kV air discharge. |
Use Scenario: Suppressing inductive kickback from H-bridge MOSFETs during PWM commutation in 24 V EPS systems. IC Role / Device Role / Timing Role: High-energy (3000 W) clamp across motor phase outputs and supply rails. Use Value: Absorbs 10/1000 µs surges up to 168 A without degradation, maintaining RD < 10 mΩ after 1000 pulses. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar bidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| Littelfuse SMAJ33CA | VBR = 36.7–40.5 V; VCL = 53.3 V @ 115 A; PPP = 400 W (10/1000 µs) | Lower surge rating - suitable only for non-load-dump sub-systems (e.g., interior lighting) | Select when cost sensitivity outweighs need for 3000 W pulse handling and AEC-Q101 validation. |
| Vishay SMA6J33CA | VBR = 36.7–40.5 V; VCL = 53.3 V @ 115 A; PPP = 600 W (10/1000 µs); AEC-Q101 qualified | Same qualification level but lower peak power - requires parallel devices for load dump duty cycles | Choose if board space allows dual-device layout and thermal management supports stacked dissipation. |
Compared with SMAJ33CA and SMA6J33CA, SM30T33CAY provides 5× higher peak pulse power (3000 W vs. ≤600 W), tighter VCL (45.4 V vs. 53.3 V), and validated performance across full ISO 7637-2 pulse set - making it the sole option for single-device protection of 12 V/24 V power rails in safety-critical ECUs.
Availability
SM30T33CAY is available at Aetrix Electronics and suitable for automotive power rail protection, ADAS sensor interface hardening, and body electronics surge suppression requiring stable component supply across multi-year production programs.
Supply support for SM30T33CAY 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 with vertical manufacturing and design expertise.
SM30T33CAY belongs to the SM30TY series - a family of AEC-Q101-qualified, high-power TVS diodes engineered specifically for ISO 7637-2 and ISO 10605 compliance in harsh automotive environments.
FAQ
What is the maximum clamping voltage of SM30T33CAY under a 168 A surge?
The maximum clamping voltage (VCL) is 45.4 V at IPP = 168 A for an 8/20 µs waveform, measured at Tj = 25 °C. This value increases linearly with junction temperature at αT = 10 × 10−4/°C, reaching ~47.2 V at Tj = 125 °C per datasheet Equation 2.
Is SM30T33CAY unidirectional or bidirectional?
SM30T33CAY is a bidirectional TVS diode, indicated by the "CAY" suffix. Its symmetrical breakdown behavior (VBR = 31.1–34.3 V in both polarities) enables protection of AC-coupled lines, differential buses, and floating grounds without polarity concerns.
Does SM30T33CAY meet AEC-Q101 requirements?
Yes - SM30T33CAY is fully AEC-Q101 qualified, with test reports covering HTGB, H3TRB, TC, UHAST, and mechanical shock per Rev 13 datasheet DS8599. It also complies with J-STD-020 MSL Level 1 and JESD201 Class 2 whisker testing.
What is the recommended PCB footprint for SM30T33CAY?
The official footprint recommendation is 5.11 mm × 8.19 mm (201 mil × 322 mil) with 1.54 mm pad extensions, matching IPC7531 and JEDEC DO-214AB standards. Copper area under each lead should be ≥2.5 cm² to maintain Rth(j-a) ≤ 100 °C/W per Figure 12.
SM30T33CAY 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):
- 28V
- Voltage - Breakdown (Min):
- 31.1V
- Voltage - Clamping (Max) @ Ipp:
- 45.4V
- Current - Peak Pulse (10/1000µs):
- 66.1A
- 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
SM30T33CAY FAQ
1.How can I place an order for SM30T33CAY through Aetrix?
Please submit a Request for Quotation (RFQ) for SM30T33CAY 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 SM30T33CAY reliable?
The price and inventory of SM30T33CAY are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SM30T33CAY is usually 5 days.
3.What payment methods are accepted for SM30T33CAY?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM30T33CAY transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SM30T33CAY?
SM30T33CAY orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SM30T33CAY 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 SM30T33CAY?
For technical support, including SM30T33CAY datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM30T33CAY requirements.
6.How does Aetrix verify that SM30T33CAY is sourced from the original manufacturer or authorized distributors?
All SM30T33CAY 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 SM30T33CAY meets industry standards.
7.What is the process for return or replacement of SM30T33CAY?
All SM30T33CAY units undergo pre-shipment inspection (PSI). If there is an issue with SM30T33CAY, 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 SM30T33CAY part is unused and in its original packaging.
Return procedure for SM30T33CAY:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SM30T33CAY Tags
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