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STMicroelectronics SM50T47AY
- Part No.:
- SM50T47AY
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SM50T47AY.pdf
- Description:
- AUTOMOTIVE 5000 W, 40 V TVS IN S
- Quantity:
- Payment:
- Shipping:
Inventory:5,155
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Product details
Overview
SM50T47AY from STMicroelectronics is a unidirectional 47 V standoff automotive TVS diode in SMC package, AEC-Q101 qualified, rated for 5000 W (10/1000 µs) peak pulse power and 199 A peak pulse current at 8/20 µs, with 64.5 V clamping voltage at 199 A and 0.2 µA leakage at 25 °C - used to protect CAN, LIN, and sensor interfaces in 12 V automotive power networks against ISO 7637-2 pulses and IEC 61000-4-2 ESD.
For engineers reviewing the SM50T47AY datasheet, SM50T47AY pinout, SM50T47AY application, or SM50T47AY equivalent, this page delivers verified electrical parameters, automotive-grade reliability data, SMC package mechanical details, ISO-compliant surge performance, and direct design guidance for e-breaker and ISO 16750-2 compliance.
Technical Context
This device employs planar junction technology to achieve low leakage (0.2 µA at 25 °C) and high junction temperature operation up to 175 °C, enabling long-term stability in under-hood environments. Its unidirectional configuration provides asymmetric clamping optimized for DC-biased lines like battery-supplied ECUs.
The 47 V nominal breakdown voltage (VBR = 44.4–49 V at 1 mA) supports systems where VRM must exceed 40 V while maintaining margin against load dump transients. Dynamic resistance (RD = 68.5 mΩ) and thermal impedance characteristics ensure predictable clamping behavior across pulse durations from 10 µs to 1000 µs.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Standoff Voltage (VRM) | 40 V - maximum continuous reverse operating voltage before significant leakage; sets minimum system DC bias tolerance. |
| Breakdown Voltage (VBR) | 44.4–49 V at 1 mA - precise conduction onset range ensures reliable triggering without premature clamping in 12 V automotive systems. |
| Clamping Voltage (VCL) | 64.5 V at 199 A (8/20 µs) - limits transient overvoltage to safe levels for downstream 65 V-rated ICs like CAN transceivers. |
| Peak Pulse Power (PPP) | 5000 W (10/1000 µs) - sustains high-energy surges per ISO 7637-2 Pulse 1 (−150 V) and Pulse 3a (−220 V) without failure. |
| Leakage Current (IRM) | 0.2 µA at 40 V, 25 °C - negligible standby power loss critical for always-on vehicle modules and low-power wake-up circuits. |
| Junction Temperature Range | −55 to +175 °C - enables deployment in engine control units, transmission controllers, and other high-temperature under-hood locations. |
| ESD Withstand | 30 kV contact & air discharge (IEC 61000-4-2) - exceeds automotive level 4 requirements for human-body-model robustness. |
Pinout & Package
SM50T47AY uses the JEDEC-standardized 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, compatible with standard reflow profiles (peak 240–245 °C).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Low-side reference terminal | Connected to ground or low-voltage return path; defines unidirectional conduction direction toward cathode. |
| Cathode | High-side surge input terminal | Connected to protected line (e.g., CAN_H); conducts transient current to ground when voltage exceeds VBR. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualification | Validated for automotive use across temperature, humidity, vibration, and lifetime stress tests - required for ECU front-end protection. |
| Planar junction construction | Enables stable 0.2 µA leakage at 25 °C and <100 nA at 125 °C - essential for low-power always-on modules. |
| ISO 7637-2 compliance | Withstands Pulse 1 (−150 V), Pulse 2a (+112 V), Pulse 3a (−220 V), and Pulse 3b (+150 V) without degradation. |
| High-temperature operation | Rated for continuous operation at Tj = 175 °C - supports placement near heat sources such as power converters or motor drivers. |
| Low dynamic resistance | RD = 68.5 mΩ - minimizes clamping voltage rise under high-current transients, improving protection margin for downstream ICs. |
Applications
| Body Control Module (BCM) | Electronic Brake System (EBS) |
|---|---|
|
Use Scenario: Protecting LIN bus lines and door actuator power feeds from battery transients during jump-start or alternator load dump. IC Role / Device Role / Timing Role: Unidirectional TVS placed between LIN transceiver supply pin and chassis ground to clamp negative-going spikes below −150 V. Use Value: Prevents latch-up or permanent damage to LIN PHY ICs rated for only −40 V absolute minimum, ensuring functional safety compliance. |
Use Scenario: Safeguarding ABS solenoid driver outputs and wheel speed sensor inputs against ISO 7637-2 Pulse 1 and Pulse 3a events. IC Role / Device Role / Timing Role: Mounted directly at connector interface to absorb −220 V (Pulse 3a) energy before it reaches analog front-end amplifiers. Use Value: Maintains signal integrity during braking events by limiting voltage excursion to ≤64.5 V, preserving ADC accuracy and fault detection timing. |
| Engine Control Unit (ECU) | Infotainment Head Unit |
|
Use Scenario: Shielding CAN FD communication lines from alternator-induced surges and ignition coil coupling in 48 V mild-hybrid architectures. IC Role / Device Role / Timing Role: Bidirectional clamping not applicable; unidirectional SM50T47AY used on CAN_H with ground-referenced layout to suppress positive transients only. Use Value: Enables CAN FD bit rates >2 Mbps by minimizing parasitic capacitance (typ. <100 pF at 0 V) and avoiding signal distortion. |
Use Scenario: Guarding USB-C and HDMI port power rails against ESD events during consumer interaction in vehicle cabins. IC Role / Device Role / Timing Role: Placed on VBUS line upstream of USB PD controller to shunt 30 kV contact discharge energy away from PMIC input stage. Use Value: Eliminates need for secondary TVS stages, reducing BOM count while meeting ISO 10605 30 kV air/contact discharge requirements. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar automotive TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ47A | Lower PPP (400 W), higher VCL (77 V at 51.2 A), SMA package (smaller thermal mass) | Not AEC-Q101 qualified; limited to non-safety-critical cabin modules | Select only for cost-sensitive, non-under-hood applications where 5000 W surge immunity is unnecessary. |
| TPSMB47A | Same SMC package, AEC-Q101 qualified, but lower IPP (170 A) and higher RD (82 mΩ) | Clamps to 67.2 V at 170 A - insufficient margin for 65 V-rated CAN FD transceivers under worst-case surge | Acceptable for legacy CAN 2.0B designs with 70 V tolerant PHYs, but not recommended for new CAN FD deployments. |
Compared with SMAJ47A and TPSMB47A, SM50T47AY delivers superior surge robustness (5000 W vs. 400 W/3000 W), tighter clamping (64.5 V vs. 77 V/67.2 V), and verified AEC-Q101 compliance - making it the only choice for ASIL-B/C front-end protection in modern ECUs and ADAS domains.
Availability
SM50T47AY is available at Aetrix Electronics and suitable for automotive body electronics, powertrain control units, and infotainment systems requiring stable component supply across extended product lifecycles and high-temperature operational environments.
Supply support for SM50T47AY 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, sensors, and analog ICs for automotive, industrial, and consumer markets.
SM50T47AY belongs to the SM50TY series - a family of planar-junction automotive TVS diodes engineered specifically for ISO 7637-2 and ISO 10605 compliance in harsh-temperature vehicle subsystems.
FAQ
What is the maximum clamping voltage of SM50T47AY under an 8/20 µs surge?
The maximum clamping voltage (VCL) is 64.5 V at 199 A for an 8/20 µs waveform, measured at 25 °C. This value increases with junction temperature at a coefficient of 10.1 × 10⁻⁴/°C, reaching approximately 67.2 V at 150 °C junction temperature.
Is SM50T47AY suitable for bidirectional signal lines like CAN differential pairs?
No - SM50T47AY is unidirectional and intended for single-ended, ground-referenced lines such as power rails or LIN buses. For CAN_H/CAN_L protection, ST recommends the bidirectional SM50T47CAY variant, which clamps symmetrically in both polarities.
How does SM50T47AY perform under ISO 7637-2 Pulse 5b (load dump)?
SM50T47AY is not rated for load dump (Pulse 5b) due to its 40 V VRM being below typical 12 V system battery voltage. It is designed for transient suppression only; load dump requires higher-VRM devices like SM50T82AY (VRM = 70 V) or dedicated load dump suppressors.
What is the thermal resistance junction-to-ambient for SM50T47AY on a standard FR4 PCB?
On a recommended footprint (3.14 cm² copper area per lead), Rth(j-a) is 40 °C/W for a single pulse. With 5 cm² total copper area, thermal resistance drops to ~32 °C/W - enabling sustained operation at 175 °C junction temperature under intermittent surge conditions.
SM50T47AY 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):
- 40V (Max)
- Voltage - Breakdown (Min):
- 44.4V
- Voltage - Clamping (Max) @ Ipp:
- 64.5V
- Current - Peak Pulse (10/1000µs):
- 78A
- 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
SM50T47AY FAQ
1.How can I place an order for SM50T47AY through Aetrix?
Please submit a Request for Quotation (RFQ) for SM50T47AY 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 SM50T47AY reliable?
The price and inventory of SM50T47AY are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SM50T47AY is usually 5 days.
3.What payment methods are accepted for SM50T47AY?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM50T47AY transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SM50T47AY?
SM50T47AY orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SM50T47AY 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 SM50T47AY?
For technical support, including SM50T47AY datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM50T47AY requirements.
6.How does Aetrix verify that SM50T47AY is sourced from the original manufacturer or authorized distributors?
All SM50T47AY 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 SM50T47AY meets industry standards.
7.What is the process for return or replacement of SM50T47AY?
All SM50T47AY units undergo pre-shipment inspection (PSI). If there is an issue with SM50T47AY, 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 SM50T47AY part is unused and in its original packaging.
Return procedure for SM50T47AY:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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