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STMicroelectronics SM6T42CAY
- Part No.:
- SM6T42CAY
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SM6T42CAY.pdf
- Description:
- TVS DIODE 36VWM 58.1VC SMB
- Quantity:
- Payment:
- Shipping:
Inventory:8,958
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Product details
Overview
SM6T42CAY from STMicroelectronics is a bidirectional automotive-grade transient voltage suppression (TVS) diode in SMB package, designed for ISO 7637-2 pulse protection (Pulse 1: −150 V; Pulse 2a: +112 V; Pulse 3a: −220 V; Pulse 3b: +150 V) and ESD robustness per ISO 10605 (±30 kV air/contact discharge). It features 42.1 V nominal breakdown voltage (VBR), 58.1 V clamping voltage (VCL) at 10.3 A (10/1000 µs), 600 W peak pulse power, and operates up to 150 °C junction temperature.
For engineers reviewing the SM6T42CAY datasheet, SM6T42CAY pinout, SM6T42CAY application, or SM6T42CAY equivalent, this component serves as a high-reliability, AEC-Q101 qualified surge protector for 12 V automotive power nets-especially critical in body control modules, infotainment power rails, and sensor interface lines where low leakage (0.2 µA @ 25 °C) and stable clamping under thermal stress are mandatory.
Technical Context
This bidirectional TVS diode uses planar silicon technology to achieve low dynamic resistance (RD = 1.35 Ω at 25 °C) and high junction temperature capability (Tj max = 150 °C), enabling sustained surge handling even in under-hood environments. Its symmetrical I-V characteristics support protection against both positive and negative transients without polarity dependency.
The device complies with ISO 7637-2 (Pulse 1, 2a, 3a, 3b), ISO 10605 (C = 150/330 pF, R = 330 Ω), and IEC 61000-4-4 Level 4 (±4 kV), and is validated for solder reflow per J-STD-020 MSL Level 1 with matte tin lead finish.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VBR (min) | 36 V - Ensures reliable conduction onset above normal 12 V system operating range, avoiding false triggering during load dump overshoots. |
| VCL @ 10.3 A (10/1000 µs) | 58.1 V - Clamps transients below automotive semiconductor absolute maximum ratings (e.g., <60 V for many MCU power pins). |
| PPP (10/1000 µs) | 600 W - Sustains common ISO 7637-2 pulses (e.g., Pulse 3b: +150 V) without degradation when mounted on recommended FR4 footprint. |
| IPP (10/1000 µs) | 10.3 A - Delivers precise current-handling margin for design validation against worst-case battery line surges. |
| RD | 1.35 Ω - Low dynamic resistance minimizes VCL rise under high-current pulses, improving protection margin. |
| Tj max | 150 °C - Enables operation in engine compartment locations without derating, supporting long-term reliability per AEC-Q101. |
| IR @ VRM = 33.3 V | 0.2 µA @ 25 °C - Ultra-low leakage preserves battery standby current in always-on vehicle modules (e.g., CAN wake-up circuits). |
Pinout & Package
SM6T42CAY is housed in an SMB (DO-214AA) surface-mount package with two terminals: Cathode (K) and Anode (A). The bidirectional configuration means both terminals behave identically under reverse bias-no polarity marking required for functional orientation, though physical marking "NA" appears on the cathode side per Table 6 of DS6905.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (A) | Transient return path (bidirectional) | Serves as low-impedance sink for both positive and negative surges relative to protected line; no DC polarity assignment. |
| Cathode (K) | Transient return path (bidirectional) | Electrically identical to Anode under surge conditions; terminal symmetry enables flexible PCB layout without orientation constraints. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualification | Validated for automotive under-hood use with temperature cycling, humidity, and mechanical shock testing per standard. |
| ISO 7637-2 compliance (Pulse 1/2a/3a/3b) | Guarantees survivability against real-world automotive transients including load dump, alternator switching, and inductive kickback. |
| ±30 kV ESD immunity (ISO 10605) | Protects downstream ICs from human-body-model and machine-model ESD events without external shielding or filtering. |
| Matte tin lead finish (JESD 22-B102 E3) | Ensures solderability and whisker resistance over lifetime, meeting IPC-7531 footprint and JEDEC outline requirements. |
| Low Tj-dependent VBR drift (αT = 10−4/°C) | Maintains consistent clamping threshold across −55 °C to +150 °C, critical for cold-cranking and hot-soak scenarios. |
Applications
| Body Control Module (BCM) Power Input | Infotainment System 12 V Rail |
|---|---|
|
Use Scenario: Protects BCM microcontroller and CAN transceiver power inputs from battery line transients during jump-starts, load dumps, and relay switching. IC Role / Device Role / Timing Role: Bidirectional clamping element placed between fused 12 V supply and local LDO input, absorbing energy before it reaches sensitive logic. Use Value: Prevents latch-up or permanent damage to 5 V/3.3 V regulators by limiting input voltage to ≤58.1 V during 100 ms ISO 7637-2 Pulse 3b events. |
Use Scenario: Shields USB-C power delivery circuitry and display backlight drivers from ESD and ignition noise in center-stack head units. IC Role / Device Role / Timing Role: First-line transient suppressor on main 12 V feed, positioned upstream of DC-DC converters and EMI filters. Use Value: Eliminates need for secondary TVS stages by withstanding ±30 kV contact discharge (ISO 10605) without parameter shift after 1000 strikes. |
| Rear Camera Power Line | Blind Spot Detection Radar Supply |
|
Use Scenario: Secures 12 V supply to rear-view camera modules exposed to trunk lid ESD and ground-loop surges. IC Role / Device Role / Timing Role: Low-leakage (0.2 µA) TVS placed directly at connector entry point to minimize parasitic capacitance impact on video signal integrity. Use Value: Maintains <1 nA standby current contribution while clamping 220 V negative transients (ISO 7637-2 Pulse 3a) within 1 ns response time. |
Use Scenario: Safeguards 12 V supply to 77 GHz radar sensors subject to vibration-induced arcing and alternator ripple coupling. IC Role / Device Role / Timing Role: High-temperature-stable protector mounted near radar module's power entry, rated for continuous 150 °C ambient operation. Use Value: Delivers 515 W surge capability at Tj = 150 °C (Figure 3), ensuring protection margin remains intact during sustained engine heat soak. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar bidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ43CA | Higher VBR (36.8–40.8 V), higher VCL (69.4 V @ 8.6 A), same SMB package | Less margin for 12 V systems near upper rail; better suited for 24 V commercial vehicles | Select if system nominal voltage is 24 V or if higher clamping voltage is acceptable for downstream overvoltage tolerance. |
| 1.5SMC43CA | Larger SMC package (7.1 × 6.2 mm), 1500 W PPP, VCL = 69.4 V @ 21.7 A | Requires more PCB area; used where higher single-pulse energy absorption is needed (e.g., alternator output) | Choose only when 600 W is insufficient and board space allows SMC footprint; not drop-in compatible due to size and thermal mass differences. |
Compared with SMBJ43CA and 1.5SMC43CA, SM6T42CAY offers tighter VBR tolerance (36–44.2 V), lower clamping (58.1 V), and AEC-Q101 qualification-making it the preferred choice for space-constrained, thermally demanding 12 V automotive nodes where precision voltage limiting and long-term reliability are non-negotiable.
Availability
SM6T42CAY is available at Aetrix Electronics and suitable for automotive body electronics, infotainment power conditioning, and ADAS sensor supply protection requiring stable component supply across multi-year production cycles.
Supply support for SM6T42CAY 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 and AEC-Q101 validation infrastructure.
The SM6TY series was developed specifically for automotive electrical system protection-targeting ISO 7637-2 and ISO 10605 compliance in compact SMB packages for integration into space-limited ECUs and sensor modules.
FAQ
What is the maximum clamping voltage of SM6T42CAY under a 10/1000 µs surge?
The maximum clamping voltage (VCL) is 58.1 V at 10.3 A for a 10/1000 µs waveform, measured at Tamb = 25 °C. This value increases linearly with junction temperature at αT = 10−4/°C, reaching ~61.5 V at Tj = 150 °C per the VCL vs. Tj formula in DS6905 Section 2.1.
Is SM6T42CAY unidirectional or bidirectional, and how is polarity identified?
SM6T42CAY is a bidirectional TVS diode-its electrical behavior is symmetric for both polarities, with no functional anode/cathode distinction during surge events. Physical marking "NA" appears on one end per Table 6, but orientation has no effect on protection performance; either terminal may connect to the protected line or ground.
Does SM6T42CAY meet AEC-Q101 requirements for automotive under-hood use?
Yes-SM6T42CAY is explicitly AEC-Q101 qualified per the datasheet front page and features Tj max = 150 °C, matte tin plating compliant with JESD 22-B102 E3, and validation against temperature cycling, humidity, and mechanical shock tests required for Grade 1 automotive components.
What is the leakage current specification at elevated temperature?
Leakage current (IR) is specified at 0.2 µA maximum at VRM = 33.3 V and Tj = 25 °C, rising to 1 µA maximum at Tj = 85 °C. Figure 9 in DS6905 shows typical IR remains below 10 nA up to 125 °C for VRM ≥ 10 V, confirming suitability for low-power always-on automotive circuits.
SM6T42CAY Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- DO-214AA, SMB
- Series:
- SM6TY, TRANSIL™
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- -
- Bidirectional Channels:
- 1
- Voltage - Reverse Standoff (Typ):
- 36V
- Voltage - Breakdown (Min):
- 40V
- Voltage - Clamping (Max) @ Ipp:
- 58.1V
- Current - Peak Pulse (10/1000µs):
- 10.3A
- Power - Peak Pulse:
- 600W
- Power Line Protection:
- No
- Applications:
- -
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMB
SM6T42CAY FAQ
1.How can I place an order for SM6T42CAY through Aetrix?
Please submit a Request for Quotation (RFQ) for SM6T42CAY 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 SM6T42CAY reliable?
The price and inventory of SM6T42CAY are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SM6T42CAY is usually 5 days.
3.What payment methods are accepted for SM6T42CAY?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM6T42CAY transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SM6T42CAY?
SM6T42CAY orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SM6T42CAY 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 SM6T42CAY?
For technical support, including SM6T42CAY datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM6T42CAY requirements.
6.How does Aetrix verify that SM6T42CAY is sourced from the original manufacturer or authorized distributors?
All SM6T42CAY 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 SM6T42CAY meets industry standards.
7.What is the process for return or replacement of SM6T42CAY?
All SM6T42CAY units undergo pre-shipment inspection (PSI). If there is an issue with SM6T42CAY, 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 SM6T42CAY part is unused and in its original packaging.
Return procedure for SM6T42CAY:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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