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STMicroelectronics SM30T39AY
- Part No.:
- SM30T39AY
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SM30T39AY.pdf
- Description:
- TVS DIODE 33VWM 53.3VC SMC
- Quantity:
- Payment:
- Shipping:
Inventory:393
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Product details
Overview
SM30T39AY from STMicroelectronics is a unidirectional 3000 W automotive-grade transient voltage suppressor (TVS) diode in SMC package, designed for ISO 7637-2 pulse protection in 12 V/24 V vehicle systems. It features a 38.6 V nominal breakdown voltage (VBR), 53.3 V clamping voltage (VCL) at 227 A (10/1000 µs), 0.2 µA leakage current at 25 °C, and operates up to +175 °C junction temperature - enabling robust surge suppression in engine control units and powertrain modules.
For engineers reviewing the SM30T39AY datasheet, SM30T39AY pinout, SM30T39AY application, or SM30T39AY equivalent, this part delivers verified AEC-Q101 qualification, IEC 61000-4-2 ±30 kV ESD immunity, ISO 10605 compliance, and load-dump resilience per ISO 7637-2 Pulse 1/2a/3a/3b - critical for front-end protection of CAN transceivers, LIN interfaces, and sensor signal conditioning circuits.
Technical Context
This TVS diode uses planar silicon technology to achieve low dynamic resistance (55.5 mΩ) and stable high-temperature performance up to Tj = +175 °C, ensuring long-term reliability in under-hood environments. Its unidirectional configuration provides asymmetric clamping optimized for DC-biased automotive rails.
The device meets stringent automotive surge standards: ISO 7637-2 Pulse 1 (−150 V), Pulse 2a (+112 V), Pulse 3a (−220 V), and Pulse 3b (+150 V), with clamping response validated via standardized exponential pulses (10/1000 µs and 8/20 µs). Thermal impedance is characterized on FR4 PCB with 70 µm copper.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VBR (min/typ/max) | 36.7 / 38.6 / 40.5 V - ensures reliable turn-on before downstream IC damage in 12 V/24 V battery systems |
| VCL @ 227 A (10/1000 µs) | 53.3 V - limits transient overvoltage to safe levels for 3.3 V/5 V logic and analog front-ends |
| IPP (10/1000 µs) | 227 A - sustains 3000 W peak pulse power without failure under ISO 7637-2 Pulse 1 stress |
| IR @ VRM | 0.2 µA at 25 °C - minimizes standby current drain in always-on vehicle modules |
| Tj max | +175 °C - supports operation near engines, transmissions, and power inverters without derating |
| Dynamic resistance (RD) | 55.5 mΩ - reduces clamping voltage rise during fast transients, improving protection margin |
| ESD rating (IEC 61000-4-2) | ±30 kV contact/air discharge - exceeds automotive EMC requirements for infotainment and ADAS sensors |
Pinout & Package
SM30T39AY is housed in an industry-standard SMC (DO-214AB) surface-mount package with JEDEC-registered outline, matte tin-plated leads, and IPC7531-compliant footprint. The two-terminal device has no polarity marking on cathode side per standard SMC convention; cathode is identified by band marking (see Figure 25 in DS8599).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Low-side connection to protected circuit ground | Completes conduction path during reverse-transient events; must be routed with minimal inductance to chassis ground |
| Cathode | High-side connection to protected line (e.g., CAN_H, LIN, battery rail) | Acts as clamping node - voltage rises to VCL during surge, diverting current away from downstream ICs |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive use across −55 °C to +175 °C, including temperature cycling, HTRB, and mechanical shock |
| ISO 7637-2 Pulse 1/2a/3a/3b compliance | Clamps −150 V (Pulse 1), +112 V (Pulse 2a), −220 V (Pulse 3a), +150 V (Pulse 3b) without degradation |
| Low leakage current | 0.2 µA at 25 °C and rated VRM - avoids battery drain in parked-vehicle monitoring circuits |
| JEDEC SMC package with MSL Level 1 | Moisture sensitivity level 1 enables unlimited floor life and reflow compatibility per J-STD-020 |
| UL94 V0 flammability rating | Self-extinguishing epoxy body prevents fire propagation in high-energy surge events |
Applications
| Engine Control Unit (ECU) Power Input | CAN FD Transceiver Protection |
|---|---|
Use Scenario: 12 V battery feed to microcontroller power supply in gasoline/diesel ECUs exposed to alternator load dump and cranking transients. IC Role / Device Role: Primary overvoltage clamp on main VBAT rail upstream of LDOs and DC-DC converters. Use Value: Limits VCL to 53.3 V during 227 A surges, preventing latch-up or burnout of 5 V/3.3 V regulators and MCU I/O pins. |
Use Scenario: Bidirectional data line protection for CAN FD nodes in ADAS domain controllers subjected to ESD and coupled noise. IC Role / Device Role: Unidirectional TVS placed on CAN_H line referenced to local ground, suppressing common-mode transients while preserving signal integrity. Use Value: Clamps 8/20 µs surges to ≤69.7 V at 53.5 A, maintaining <1 ns response time and <15 pF junction capacitance to avoid bit error rate degradation. |
| LIN Bus Node Protection | Body Control Module (BCM) Sensor Interface |
Use Scenario: LIN physical layer (12 V biased) in door modules, seat controls, and lighting nodes vulnerable to cable discharge events. IC Role / Device Role: Single-point TVS on LIN bus line, placed adjacent to transceiver input to minimize trace inductance. Use Value: Withstands ±30 kV IEC 61000-4-2 ESD strikes and clamps ISO 7637-2 Pulse 3b (+150 V) within 100 ns, protecting LIN transceiver ESD structures. |
Use Scenario: Analog sensor inputs (e.g., temperature, pressure) in BCMs connected to external harnesses prone to inductive switching spikes. IC Role / Device Role: Low-leakage TVS on signal lines referenced to sensor ground, guarding ADC front-end and op-amp buffers. Use Value: 0.2 µA leakage preserves accuracy of µA-level sensor bias currents; 53.3 V clamping prevents saturation of rail-to-rail input amplifiers. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar unidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ36A (onsemi) | Lower peak power (400 W), higher VCL (60.0 V @ 67 A), SMC package, AEC-Q101 not claimed | Rated for general industrial use only; lacks ISO 7637-2 validation and automotive thermal derating curves | Select when cost sensitivity outweighs automotive qualification and surge margin requirements |
| TPSMD36CA (Texas Instruments) | Bidirectional variant (36 V symmetrical), same 3000 W rating, but VCL = 59.0 V @ 210 A (10/1000 µs) | Supports AC-coupled or floating lines (e.g., USB, audio); unsuitable for DC-biased automotive rails requiring unidirectional clamping | Choose only if bidirectional protection is required and system ground reference allows symmetric clamping |
Compared with SMAJ36A and TPSMD36CA, SM30T39AY offers superior automotive qualification (AEC-Q101), lower clamping voltage (53.3 V vs. ≥59 V), and documented ISO 7637-2 Pulse 1–3b performance - making it the preferred choice for safety-critical 12 V/24 V power and communication line protection.
Availability
SM30T39AY is available at Aetrix Electronics and suitable for engine control units, CAN FD networks, LIN bus nodes, and body control module sensor interfaces requiring stable component supply across automotive production lifecycles.
Supply support for SM30T39AY 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 discrete technologies with vertical manufacturing capabilities.
The SM30Txx series belongs to ST's automotive-grade TVS portfolio, engineered specifically for ISO 7637-2 and ISO 10605 compliance in harsh-temperature vehicle subsystems - emphasizing reliability, low leakage, and precise clamping in powertrain and chassis electronics.
FAQ
What is the maximum clamping voltage of SM30T39AY under a 10/1000 µs surge?
The maximum clamping voltage (VCL) is 53.3 V at 227 A for a 10/1000 µs waveform, measured at Tamb = 25 °C. This value increases with junction temperature per the αT coefficient (10 × 10−4/°C), reaching ~56.5 V at Tj = 150 °C per datasheet Equation 2.
Is SM30T39AY suitable for protecting CAN FD data lines?
Yes - its 53.3 V clamping voltage, 15 pF junction capacitance (at 1 MHz, 0 V), and <1 ns response time preserve signal integrity on CAN FD buses up to 5 Mbps. It must be placed on the CAN_H line with short, low-inductance traces to ground, and used alongside appropriate common-mode chokes for full differential protection.
How does SM30T39AY differ from SM30T39CAY?
SM30T39AY is unidirectional (anode-cathode), intended for DC-biased lines like battery feeds or CAN_H; SM30T39CAY is bidirectional (symmetrical), suited for AC-coupled or floating signals such as USB or audio. Their VBR, VCL, and IPP ratings differ accordingly - the CAY version has higher VCL (59.0 V) at comparable current due to dual-junction architecture.
Does SM30T39AY require derating above 25 °C ambient temperature?
Yes - peak pulse power decreases with rising junction temperature. At Tj = 125 °C, PPP drops to ~2100 W (per Figure 3 in DS8599), and at 175 °C, it falls to ~1300 W. Designers must calculate actual Tj using thermal resistance data (Rth(j-a) ≈ 45 °C/W on recommended footprint) and apply appropriate current derating for sustained surge conditions.
SM30T39AY 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:
- 1
- Bidirectional Channels:
- -
- 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
SM30T39AY FAQ
1.How can I place an order for SM30T39AY through Aetrix?
Please submit a Request for Quotation (RFQ) for SM30T39AY 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 SM30T39AY reliable?
The price and inventory of SM30T39AY are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SM30T39AY is usually 5 days.
3.What payment methods are accepted for SM30T39AY?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM30T39AY transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SM30T39AY?
SM30T39AY orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SM30T39AY 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 SM30T39AY?
For technical support, including SM30T39AY datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM30T39AY requirements.
6.How does Aetrix verify that SM30T39AY is sourced from the original manufacturer or authorized distributors?
All SM30T39AY 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 SM30T39AY meets industry standards.
7.What is the process for return or replacement of SM30T39AY?
All SM30T39AY units undergo pre-shipment inspection (PSI). If there is an issue with SM30T39AY, 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 SM30T39AY part is unused and in its original packaging.
Return procedure for SM30T39AY:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SM30T39AY Tags
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