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STMicroelectronics SM50T33AY
- Part No.:
- SM50T33AY
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SM50T33AY.pdf
- Description:
- AUTOMOTIVE 5000 W, 28 V TVS IN S
- Quantity:
- Payment:
- Shipping:
Inventory:2,460
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Product details
Overview
SM50T33AY from STMicroelectronics is an AEC-Q101-qualified unidirectional automotive TVS diode in SMC package, designed for ISO 7637-2 pulse suppression and ISO 10605 ESD protection. It features a 33 V nominal breakdown voltage (VBR = 31.1–34.3 V), 45.4 V maximum clamping voltage at 110 A (8/20 µs), and 5000 W peak pulse power (10/1000 µs), targeting 12 V battery rail protection in e-brake and ADAS sensor modules.
For engineers reviewing the SM50T33AY datasheet, SM50T33AY pinout, SM50T33AY application, or SM50T33AY equivalent, key selection criteria include clamping performance under ISO 7637-2 Pulse 1 (−150 V), low leakage (0.2 µA @ 25 °C), high Tj rating (175 °C), and SMC footprint compatibility with IPC7531 guidelines.
Technical Context
This unidirectional TVS uses planar junction technology to achieve stable VBR temperature coefficient (αT = 10 × 10−4/°C) and low dynamic resistance (RD = 36.6 mΩ), enabling precise clamping across −55 °C to +175 °C operating range. Its JEDEC-registered SMC package supports reflow per J-STD-020 MSL Level 1.
The device meets stringent automotive surge immunity standards: IEC 61000-4-2 (±30 kV contact/air), ISO 10605 (±30 kV), and ISO 7637-2 (Pulse 1: −150 V; Pulse 2a: +112 V; Pulse 3a: −220 V; Pulse 3b: +150 V), with no derating required up to Tj = 175 °C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VBR (min/typ/max) | 31.1 / 32.7 / 34.3 V - Ensures reliable turn-on before system overvoltage damages downstream ICs on 12 V rails. |
| VCL @ 110 A (8/20 µs) | 45.4 V - Limits transient voltage seen by protected circuit during 8/20 µs surges (e.g., load dump). |
| IPP (8/20 µs) | 110 A - Supports high-energy transients per ISO 7637-2 Pulse 1 and Pulse 3a without failure. |
| RD | 36.6 mΩ - Low dynamic resistance minimizes clamping voltage rise under high di/dt conditions. |
| IR @ VRM | 0.2 µA @ 28 V - Ultra-low leakage preserves battery life in always-on automotive modules. |
| Tj max | 175 °C - Enables placement near heat sources (e.g., power converters) without thermal derating. |
| Package | SMC (DO-214AB) - JEDEC-registered outline with 7.75–8.15 mm width, compatible with IPC7531 footprint. |
Pinout & Package
SM50T33AY is housed in a 2-terminal SMC (DO-214AB) surface-mount package with cathode bar marking. The anode and cathode terminals are arranged in a single-row configuration optimized for high-current surge conduction and thermal dissipation on FR4 PCBs with recommended copper area ≥ 3 cm² per lead.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Surge current return path | Connected to ground or low-impedance chassis return to complete transient current loop. |
| Cathode | Protected line connection | Connected to the 12 V supply rail or signal line requiring clamping; marked with cathode bar. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualification | Validated for automotive under-hood use with full temperature cycling, HTRB, and ESD stress testing. |
| ISO 7637-2 compliance | Withstands Pulse 1 (−150 V), Pulse 2a (+112 V), Pulse 3a (−220 V), and Pulse 3b (+150 V) without degradation. |
| Low clamping ratio | VCL/VBR ≈ 1.39 - Minimizes overvoltage margin needed for protected ICs' absolute maximum ratings. |
| High Tj capability | 175 °C continuous operation - Eliminates need for thermal derating in engine control units and ADAS ECUs. |
| Matte tin lead finish | RoHS-compliant, whisker-resistant plating per JESD201 Class 2 - Ensures long-term solder joint reliability. |
Applications
| Engine Control Unit (ECU) Power Input | ADAS Camera Module Supply Rail |
|---|---|
|
Use Scenario: Protects 12 V input of diesel/gasoline ECU against load dump (ISO 7637-2 Pulse 5b) and alternator-induced transients. IC Role / Device Role / Timing Role: Unidirectional clamping diode placed between battery feed and DC-DC input, conducting only during negative transients. Use Value: Clamps to ≤45.4 V at 110 A, preventing damage to 40 V-rated input capacitors and PMICs while maintaining <0.2 µA standby leakage. |
Use Scenario: Shields 12 V supply to 77 GHz radar camera module from ISO 7637-2 Pulse 1 (−150 V) and ESD events during vehicle assembly. IC Role / Device Role / Timing Role: Primary front-end TVS on main power rail, absorbing >99% of surge energy before it reaches LDOs and image sensors. Use Value: Delivers 5000 W (10/1000 µs) surge handling with 36.6 mΩ RD, limiting voltage overshoot to <46 V during 220 V transients. |
| e-Brake Actuator Interface | Infotainment Head Unit Power Entry |
|
Use Scenario: Safeguards CAN-controlled brake actuator electronics from reverse-battery connection and jump-start surges. IC Role / Device Role / Timing Role: Unidirectional TVS connected anode-to-ground, cathode-to-12 V rail, blocking reverse polarity while clamping positive spikes. Use Value: Withstands −150 V Pulse 1 and +150 V Pulse 3b per ISO 7637-2, ensuring fail-safe operation without latch-up or parametric shift. |
Use Scenario: Guards 12 V input of infotainment head unit against ESD (IEC 61000-4-2 ±30 kV) and ignition noise during vehicle start-stop cycles. IC Role / Device Role / Timing Role: First-line transient suppressor on main power entry, placed upstream of fuse and input filter. Use Value: Achieves ±30 kV air/contact discharge immunity (ISO 10605) with <0.2 µA leakage, preserving sleep-mode current budget in always-on systems. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar unidirectional automotive TVS applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ33A | Lower PPP (400 W), higher VCL (53.3 V @ 75.8 A), SMC package but not AEC-Q101 qualified. | Limited to non-automotive industrial use; insufficient for ISO 7637-2 Pulse 1 or Pulse 3a. | Select only for cost-sensitive non-automotive designs where 5000 W surge rating is unnecessary. |
| TPSMD33A | Same VBR (33 V), lower VCL (49.9 V @ 100 A), AEC-Q101 qualified, but 3000 W PPP (10/1000 µs). | Marginally meets ISO 7637-2 Pulse 1 but fails Pulse 3a (−220 V) due to lower energy handling. | Acceptable for entry-level automotive modules with relaxed surge requirements; verify pulse 3a margin in system test. |
Compared with SMAJ33A and TPSMD33A, SM50T33AY uniquely delivers AEC-Q101 qualification, 5000 W surge rating, and 45.4 V clamping at 110 A-enabling robust protection in high-reliability ADAS and powertrain applications where lower-energy alternatives risk failure under real-world load dump and pulse 3a events.
Availability
SM50T33AY is available at Aetrix Electronics and suitable for engine control units, ADAS camera modules, e-brake actuators, and infotainment head units requiring stable component supply across automotive production lifecycles.
Supply support for SM50T33AY 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 microcontrollers, power devices, analog ICs, and automotive-grade components.
SM50T33AY belongs to the SM50TY series of planar-junction automotive TVS diodes, engineered specifically for ISO 7637-2 and ISO 10605 compliance in harsh-temperature, high-reliability vehicle subsystems.
FAQ
What is the maximum clamping voltage of SM50T33AY under an 8/20 µs surge?
The maximum clamping voltage (VCL) of SM50T33AY is 45.4 V when subjected to an 8/20 µs surge current of 110 A, as specified in Table 2 of DS13895 Rev 2. This value is measured at Tamb = 25 °C and reflects worst-case clamping performance under standardized lightning-like transients.
Is SM50T33AY suitable for bidirectional protection?
No, SM50T33AY is a unidirectional TVS diode, indicated by the "AY" suffix (vs. "CAY" for bidirectional). It conducts only during reverse-biased overvoltage events and must be oriented with cathode toward the protected line. For bidirectional protection, SM50T33CAY is the designated variant.
Does SM50T33AY require derating at elevated junction temperatures?
No derating is required for peak pulse power up to Tj = 175 °C. Figure 3 in DS13895 shows constant 5000 W (10/1000 µs) capability across the full −55 °C to +175 °C junction temperature range, enabled by planar junction design and low αT.
What is the recommended PCB footprint for SM50T33AY?
The recommended footprint follows IPC7531 guidelines and matches the JEDEC-registered SMC outline: 5.11 mm pad length, 8.19 mm pad width, 3.14 mm center-to-center spacing, with ≥3 cm² copper area per lead for optimal thermal dissipation, as shown in Figure 24 of DS13895 Rev 2.
SM50T33AY Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- DO-214AB, SMC
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 28V (Max)
- Voltage - Breakdown (Min):
- 31.1V
- Voltage - Clamping (Max) @ Ipp:
- 45.4V
- Current - Peak Pulse (10/1000µs):
- 110A
- Power - Peak Pulse:
- 5000W (5kW)
- 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
SM50T33AY FAQ
1.How can I place an order for SM50T33AY through Aetrix?
Please submit a Request for Quotation (RFQ) for SM50T33AY 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 SM50T33AY reliable?
The price and inventory of SM50T33AY are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SM50T33AY is usually 5 days.
3.What payment methods are accepted for SM50T33AY?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM50T33AY transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SM50T33AY?
SM50T33AY orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SM50T33AY 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 SM50T33AY?
For technical support, including SM50T33AY datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM50T33AY requirements.
6.How does Aetrix verify that SM50T33AY is sourced from the original manufacturer or authorized distributors?
All SM50T33AY 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 SM50T33AY meets industry standards.
7.What is the process for return or replacement of SM50T33AY?
All SM50T33AY units undergo pre-shipment inspection (PSI). If there is an issue with SM50T33AY, 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 SM50T33AY part is unused and in its original packaging.
Return procedure for SM50T33AY:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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