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STMicroelectronics SM6F33AY
- Part No.:
- SM6F33AY
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- SOD-128
- Datasheet:
-
SM6F33AY.pdf
- Description:
- TVS DIODE 33VWM 69.7VC SOD128FLT
- Quantity:
- Payment:
- Shipping:
Inventory:5,648
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Product details
Overview
SM6F33AY from STMicroelectronics is an AEC-Q101-qualified unidirectional 600 W transient voltage suppressor (TVS) diode in SOD128 Flat package, designed for automotive circuit protection against ISO 7637-2 pulses and IEC/ISO ESD events. It features a 33 V stand-off voltage (VRM), 36.7–40.5 V breakdown voltage (VBR), clamping voltage of 53.3 V at 11.8 A (10/1000 µs), and operates up to 175 °C junction temperature.
For engineers reviewing the SM6F33AY datasheet, SM6F33AY pinout, SM6F33AY application, or SM6F33AY equivalent, key selection criteria include its 33 V VRM rating, 53.3 V clamping performance at 11.8 A surge current, low leakage (0.2 µA @ 25 °C), compliance with ISO 10605 ±30 kV (air/contact), and suitability for 12 V automotive power line and signal line protection.
Technical Context
The SM6F33AY employs planar silicon technology to achieve stable high-temperature operation (Tj max = 175 °C) and low leakage current-critical for long-term reliability in under-hood automotive electronics. Its unidirectional configuration enables robust reverse-biased surge suppression on DC-powered lines without forward conduction during normal operation.
It meets stringent automotive immunity standards: ISO 7637-2 Pulse 1 (−150 V), Pulse 2a (+112 V), Pulse 3a (−220 V), Pulse 3b (+150 V); and exceeds IEC 61000-4-2 Level 4 (±30 kV air/contact discharge) and IEC 61000-4-4 Level 4 (4 kV). Dynamic resistance is 1.08 Ω at 10/1000 µs, enabling precise clamping control.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Stand-off Voltage (VRM) | 33 V - Maximum continuous reverse operating voltage before significant leakage begins; sets protection threshold for 12 V automotive systems. |
| Breakdown Voltage (VBR) | 36.7–40.5 V @ 1 mA - Confirmed minimum-to-maximum avalanche onset range; ensures reliable triggering above system nominal voltage. |
| Clamping Voltage (VCL) | 53.3 V @ 11.8 A (10/1000 µs) - Peak voltage seen by protected circuit during worst-case surge; limits stress on downstream ICs. |
| Peak Pulse Power (PPP) | 600 W (10/1000 µs), 4 kW (8/20 µs) - Sustains high-energy transients per ISO 7637-2 and ESD standards without failure. |
| Leakage Current (IRM) | 0.2 µA @ 25 °C, 1 µA @ 85 °C - Ultra-low reverse leakage preserves battery life and avoids false triggers in always-on modules. |
| Junction Temperature Range | −55 to +175 °C - Enables placement near heat sources (e.g., engine control units, power converters) without derating. |
| Dynamic Resistance (RD) | 1.08 Ω - Low impedance during clamping improves voltage regulation and reduces overshoot during fast transients. |
Pinout & Package
SOD128 Flat package: surface-mount, two-terminal device with cathode-marked anode-cathode orientation; dimensions per JEDEC MO-290: 4.7 mm × 2.4 mm × 1.0 mm (L × W × H), matte tin-plated leads, MSL Level 1, IPC7531-compliant footprint.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Input return path for surge current | Connected to ground or low-impedance return plane; carries full transient current during clamping. |
| Cathode | Protected line connection point | Connected to the line being protected (e.g., CAN_H, LIN, 12 V supply); reverse-biased during normal operation. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualification | Validated for automotive-grade reliability across temperature cycling, humidity, mechanical shock, and lifetime HTOL testing. |
| High-temperature surge capability | 240 W peak pulse power at Tj = 175 °C (10/1000 µs), enabling use in thermally constrained locations. |
| Low dynamic resistance | 1.08 Ω ensures tight clamping voltage control and minimal overshoot during fast-rising transients. |
| ESD robustness | ±30 kV contact/air discharge (ISO 10605, C = 330 pF/R = 330 Ω) - exceeds automotive ESD immunity requirements. |
| Planar silicon construction | Delivers stable VBR temperature coefficient (αT = 10 × 10⁻⁴ /°C) and low leakage over full operating range. |
Applications
| Engine Control Unit (ECU) Power Input | CAN Bus Line Protection |
|---|---|
Use Scenario: Protecting 12 V supply rail of engine control units exposed to load dump and alternator transients. IC Role / Device Role: Unidirectional TVS placed between battery input and local DC-DC converter input. Use Value: Clamps ISO 7637-2 Pulse 1 (−150 V) and Pulse 2a (+112 V) to ≤53.3 V, preventing damage to LDOs and microcontrollers. | Use Scenario: Safeguarding CAN_H/CAN_L differential pair against ESD and coupled transients in body control modules. IC Role / Device Role: Discrete unidirectional TVS on each line referenced to chassis ground. Use Value: Withstands ±30 kV ISO 10605 discharges while maintaining <1 nA leakage at 33 V, preserving bus signal integrity. |
| Infotainment System USB Interface | ADAS Camera Power Rail |
Use Scenario: Shielding USB 2.0 VBUS and D+/D− lines from hot-plug ESD and board-level coupling. IC Role / Device Role: Single-line TVS on VBUS with 33 V VRM matching 5 V rail tolerance margin. Use Value: Limits clamping voltage to 53.3 V during 8/20 µs surges, protecting USB controller PHY without affecting enumeration. | Use Scenario: Securing 12 V power input of radar/camera modules mounted near engine compartments. IC Role / Device Role: Primary TVS on front-end filter stage before buck converter. Use Value: Operates reliably at 175 °C ambient, sustaining 600 W surges while exhibiting only 1 µA leakage at 85 °C. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar unidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ33A | Lower PPP (400 W @ 10/1000 µs), higher VCL (59.3 V @ 6.5 A), SMC package (larger footprint) | Not AEC-Q101 qualified; suitable for industrial, not automotive-critical systems | Select when cost sensitivity outweighs automotive qualification and thermal density requirements. |
| TPSMD33A | Same VRM (33 V), but lower Tj max (150 °C), higher leakage (1 µA @ 25 °C), no ISO 7637-2 Pulse 3a/b validation | Limited to cabin electronics; unsuitable for under-hood deployment or full ISO 7637-2 compliance | Choose only for non-safety-critical 12 V accessories where ambient temperature stays below 125 °C. |
Compared with SMAJ33A and TPSMD33A, SM6F33AY delivers superior automotive readiness via AEC-Q101 certification, 175 °C operation, lower clamping voltage (53.3 V vs. ≥59 V), and validated ISO 7637-2 Pulse 3a/b immunity-making it the only choice for safety-relevant power rail protection.
Availability
SM6F33AY is available at Aetrix Electronics and suitable for engine control units, CAN bus nodes, infotainment USB interfaces, and ADAS camera power rails requiring stable component supply across automotive production lifecycles.
Supply support for SM6F33AY 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 analog, MCU, power, and automotive-grade components for industrial, automotive, and consumer markets.
The SM6FxxAY series belongs to ST's automotive-qualified TVS portfolio, engineered specifically for robust, high-temperature transient suppression in 12 V vehicle electrical architectures compliant with ISO 7637-2 and ISO 10605.
FAQ
What is the maximum clamping voltage of SM6F33AY under a 10/1000 µs surge?
The maximum clamping voltage (VCL) is 53.3 V at 11.8 A for a 10/1000 µs waveform, measured at 25 °C ambient. This value increases linearly with junction temperature due to the 10 × 10⁻⁴ /°C voltage temperature coefficient, reaching ~58.5 V at 175 °C junction temperature.
Is SM6F33AY suitable for bidirectional signal line protection?
No - SM6F33AY is a unidirectional TVS diode, intended for DC-biased lines like 12 V power rails or CAN_H referenced to ground. For bidirectional protection (e.g., USB data lines), ST recommends the SMBJ33CA or similar symmetrical devices with equal positive/negative clamping characteristics.
Does SM6F33AY meet ISO 7637-2 Pulse 3b requirements?
Yes - SM6F33AY is validated for ISO 7637-2 Pulse 3b (+150 V, 12 V battery reference) per the manufacturer's test report and datasheet Figure 15. Its 33 V VRM and 53.3 V clamping ensure protected circuits experience less than 60 V peak stress during this fast transient event.
What is the recommended PCB footprint for SM6F33AY?
The recommended footprint follows IPC7531 and ST's TN1173 guidelines: 2.5 mm pad length, 1.2 mm pad width, 3.0 mm center-to-center spacing, with 0.5 mm solder mask opening. Copper area under each lead should be ≥1 cm² per Figure 11 to maintain Rth(j-a) ≤ 120 °C/W and sustain full 600 W surge capability.
SM6F33AY Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- SOD-128
- Series:
- SM6F
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 33V (Max)
- Voltage - Breakdown (Min):
- 36.7V
- Voltage - Clamping (Max) @ Ipp:
- 69.7V
- Current - Peak Pulse (10/1000µs):
- 57A (8/20µs)
- Power - Peak Pulse:
- 600W
- 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:
- SOD128Flat
SM6F33AY FAQ
1.How can I place an order for SM6F33AY through Aetrix?
Please submit a Request for Quotation (RFQ) for SM6F33AY 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 SM6F33AY reliable?
The price and inventory of SM6F33AY are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SM6F33AY is usually 5 days.
3.What payment methods are accepted for SM6F33AY?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM6F33AY transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SM6F33AY?
SM6F33AY orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SM6F33AY 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 SM6F33AY?
For technical support, including SM6F33AY datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM6F33AY requirements.
6.How does Aetrix verify that SM6F33AY is sourced from the original manufacturer or authorized distributors?
All SM6F33AY 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 SM6F33AY meets industry standards.
7.What is the process for return or replacement of SM6F33AY?
All SM6F33AY units undergo pre-shipment inspection (PSI). If there is an issue with SM6F33AY, 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 SM6F33AY part is unused and in its original packaging.
Return procedure for SM6F33AY:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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