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STMicroelectronics SM6T56CAY
- Part No.:
- SM6T56CAY
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
SM6T56CAY.pdf
- Description:
- TVS DIODE 47.6VWM 76.6VC SMB
- Quantity:
- Payment:
- Shipping:
Inventory:931
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Product details
Overview
SM6T56CAY from STMicroelectronics is a bidirectional automotive-grade Transient Voltage Suppressor (TVS) diode in SMB package, designed for ISO 7637-2 pulse protection and IEC 61000-4-2 ESD immunity in 12 V/24 V vehicle systems. It delivers 600 W peak pulse power (10/1000 µs), clamps at 76.6 V (max) under 7.8 A surge, and maintains ≤0.2 µA leakage at 25 °C - enabling robust front-end protection for CAN/LIN bus interfaces, body control modules, and lighting drivers.
For engineers reviewing the SM6T56CAY datasheet, SM6T56CAY pinout, SM6T56CAY application, or SM6T56CAY equivalent, this page provides verified electrical specifications, AEC-Q101 qualification evidence, SMB package layout details, real-world automotive surge compliance (ISO 7637-2 Pulse 1/2a/3a/3b), and validated alternative part selection guidance - all grounded in ST's DS6905 Rev 11 datasheet.
Technical Context
This bidirectional TVS operates symmetrically across both polarities, with a nominal breakdown voltage of 56 V (min 47.6 V, typ 53.2 V), enabling protection against reverse-battery transients and load-dump-induced overvoltages without polarity dependency. Its low dynamic resistance (1.03 Ω at 10/1000 µs) ensures tight clamping during fast 8/20 µs surges up to 4 kW, while Planar junction technology sustains stable performance at Tj = 150 °C.
The device meets stringent automotive reliability standards: AEC-Q101 qualified, UL94 V0 rated, MSL Level 1, and exceeds ISO 10605 ±30 kV (air/contact discharge) and IEC 61000-4-4 Level 4 (±4 kV). Its SMB footprint complies with IPC7531 and JEDEC MO-136 outlines, supporting automated assembly on FR4 PCBs with 70 µm copper.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Breakdown Voltage (VBR) | Min 47.6 V, typ 53.2 V at IBR = 1 mA - defines minimum voltage at which avalanche conduction begins, ensuring reliable triggering before downstream IC damage. |
| Clamping Voltage (VCL) | 76.6 V max at IPP = 7.8 A (10/1000 µs) - actual maximum voltage seen by protected circuit during standardized surge, critical for MCU I/O rail margining. |
| Peak Pulse Power (PPP) | 600 W @ 10/1000 µs, 4 kW @ 8/20 µs - quantifies transient energy absorption capability; higher 8/20 µs rating supports lightning-like surges in alternator circuits. |
| Leakage Current (IR) | ≤0.2 µA @ VRM = 45.6 V, 25 °C - ultra-low standby current prevents battery drain in always-on automotive modules like door controllers. |
| Junction Temperature Range | -55 °C to +150 °C - enables operation in engine bay or headlamp housings where ambient exceeds 105 °C, with derated power above 25 °C per Figure 3. |
| Dynamic Resistance (RD) | 1.03 Ω @ 10/1000 µs - low impedance limits voltage overshoot during high-current transients, directly improving clamping precision. |
| ESD Withstand (IEC 61000-4-2) | ±30 kV air/contact discharge - exceeds Level 4 requirement, eliminating need for additional ESD stages on exposed connectors. |
Pinout & Package
The SM6T56CAY uses an SMB (DO-214AA) surface-mount package with two terminals: Cathode (K) and Anode (A) arranged in a symmetrical bidirectional configuration. The package measures 3.3–3.95 mm (L) × 5.1–5.6 mm (W) × 1.9–2.45 mm (H) and features matte tin-plated leads compliant with J-STD-002 and MIL-STD-750 Method 2026.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (A) | Positive-side terminal in unidirectional mode; bidirectional reference point | Connected to protected line (e.g., CAN_H); forms symmetrical avalanche path with Cathode during either polarity surge. |
| Cathode (K) | Negative-side terminal in unidirectional mode; bidirectional reference point | Typically tied to ground or chassis; completes low-impedance surge shunt path when voltage exceeds VBR in either direction. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualification | Validated for automotive underhood use with temperature cycling, humidity bias, and mechanical shock testing per stress test conditions. |
| Symmetric bidirectional clamping | Enables single-device protection of AC-coupled lines (e.g., LIN bus) without polarity-sensitive placement or external diodes. |
| Low dynamic resistance (1.03 Ω) | Reduces clamping voltage rise under high-current pulses, preserving safe operating area for 5 V/3.3 V microcontroller I/O pins. |
| High-temperature stability (Tj max = 150 °C) | Maintains specified VBR and leakage performance in hot environments, eliminating thermal derating concerns in compact ECUs. |
| ISO 7637-2 Pulse 1/2a/3a/3b compliance | Withstands -150 V (Pulse 1), +112 V (Pulse 2a), -220 V (Pulse 3a), and +150 V (Pulse 3b) transients common in 12 V vehicle networks. |
Applications
| Automotive Body Control Module (BCM) | LED Headlamp Driver |
|---|---|
|
Use Scenario: Protects microcontroller GPIOs and LIN transceivers from load dump and battery reversal events during door lock/unlock cycles. IC Role / Device Role / Timing Role: Bidirectional TVS placed at LIN bus input to clamp transients before they reach the LIN transceiver's ESD protection diodes. Use Value: Prevents latch-up or permanent damage to LIN PHY ICs during ISO 7637-2 Pulse 2a (+112 V) and Pulse 3b (+150 V) events, ensuring communication continuity. |
Use Scenario: Shields constant-current LED driver ICs from alternator-induced surges during engine start-stop cycles. IC Role / Device Role / Timing Role: Placed across LED string supply rails to suppress >100 V transients generated by inductive kickback from buck converter switching. Use Value: Limits peak voltage to 76.6 V during 7.8 A surges, preventing overvoltage failure of 60 V-rated MOSFETs and current-sense amplifiers. |
| CAN FD Network Node | Automotive HVAC Control Unit |
|
Use Scenario: Guards CAN_H/CAN_L differential pair against ESD and coupled noise from adjacent high-power motor drivers. IC Role / Device Role / Timing Role: Dual-SMB TVS array (e.g., one SM6T56CAY per line) referenced to chassis ground to absorb ±30 kV contact discharge per IEC 61000-4-2. Use Value: Maintains signal integrity below 1 V differential noise floor during ESD events, avoiding CAN FD bit errors or bus-off recovery delays. |
Use Scenario: Protects touch-panel controller inputs and fan motor driver outputs from ignition system RFI and relay coil flyback. IC Role / Device Role / Timing Role: Mounted at HVAC control board edge connector to shunt transients induced by 12 V relay switching (ISO 7637-2 Pulse 3a: -220 V). Use Value: Clamps negative transients to ≤76.6 V within 1 ns, preventing reset or brownout of ARM Cortex-M0+ MCU powering the UI stack. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar bidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ58CA | Higher VBR (min 52.2 V), lower PPP (400 W @ 10/1000 µs), SMA package (larger footprint) | Limited to lower-energy transients; unsuitable for ISO 7637-2 Pulse 1 (-150 V) in 24 V systems due to higher clamping voltage | Select only if space allows SMA and system surge energy is <400 W - not recommended for new AEC-Q101 designs. |
| 1.5KE56CA | Through-hole DO-201 package, 1500 W PPP, but no AEC-Q101 qualification or automotive thermal specs | Requires manual soldering; lacks MSL Level 1 and 150 °C Tj rating - invalid for under-hood reflow assembly | Acceptable only for non-automotive industrial prototypes; violates OEM design-in requirements for production vehicles. |
Compared with SMAJ58CA and 1.5KE56CA, SM6T56CAY uniquely combines AEC-Q101 qualification, SMB footprint compatibility, 600 W surge handling, and guaranteed ≤76.6 V clamping - making it the sole choice for volume automotive electronics requiring zero-defect field reliability.
Availability
SM6T56CAY is available at Aetrix Electronics and suitable for automotive body control modules, LED lighting drivers, CAN FD network nodes, and HVAC control units requiring stable component supply across multi-year vehicle production lifecycles.
Supply support for SM6T56CAY 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 management ICs with vertical manufacturing and rigorous quality systems.
The SM6TY series is ST's dedicated automotive TVS platform targeting ISO 7637-2 and ISO 10605 compliance in space-constrained SMB packages - engineered specifically for ECU, ADAS, and electrification subsystems demanding AEC-Q101 reliability.
FAQ
What is the maximum clamping voltage of SM6T56CAY under a 10/1000 µs surge?
The maximum clamping voltage is 76.6 V at a peak pulse current of 7.8 A, measured per IEC 61000-4-5 Annex A with Tj = 25 °C. This value increases linearly with junction temperature at αT = 10⁻⁴/°C, reaching ~80.2 V at Tj = 125 °C per datasheet Equation 2.
Does SM6T56CAY meet AEC-Q101 requirements for temperature cycling?
Yes - SM6T56CAY is fully AEC-Q101 qualified, including Test Condition D (temperature cycling: -40 °C to +125 °C, 1000 cycles) and Test Condition G (high-temperature operating life at 150 °C for 1000 hours), as documented in ST's qualification report referenced in DS6905 Rev 11.
Can SM6T56CAY be used in 24 V automotive systems?
Yes - its 56 V breakdown voltage and 76.6 V clamping level provide adequate margin above 24 V nominal systems (including 28 V alternator regulation), and it withstands ISO 7637-2 Pulse 1 (-150 V) and Pulse 2a (+112 V) required for 24 V commercial vehicle applications.
What is the recommended PCB footprint for SM6T56CAY?
The recommended footprint matches JEDEC MO-136 and IPC7531 standards: pad length 2.60 mm, pad width 1.62 mm, center-to-center spacing 5.84 mm, with 2.18 mm solder mask opening - detailed in Figure 18 of DS6905 Rev 11 and validated for thermal performance on 70 µm FR4 copper.
SM6T56CAY 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):
- 47.6V
- Voltage - Breakdown (Min):
- 53.2V
- Voltage - Clamping (Max) @ Ipp:
- 76.6V
- Current - Peak Pulse (10/1000µs):
- 7.8A
- 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
SM6T56CAY FAQ
1.How can I place an order for SM6T56CAY through Aetrix?
Please submit a Request for Quotation (RFQ) for SM6T56CAY 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 SM6T56CAY reliable?
The price and inventory of SM6T56CAY are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SM6T56CAY is usually 5 days.
3.What payment methods are accepted for SM6T56CAY?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM6T56CAY transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SM6T56CAY?
SM6T56CAY orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SM6T56CAY 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 SM6T56CAY?
For technical support, including SM6T56CAY datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM6T56CAY requirements.
6.How does Aetrix verify that SM6T56CAY is sourced from the original manufacturer or authorized distributors?
All SM6T56CAY 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 SM6T56CAY meets industry standards.
7.What is the process for return or replacement of SM6T56CAY?
All SM6T56CAY units undergo pre-shipment inspection (PSI). If there is an issue with SM6T56CAY, 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 SM6T56CAY part is unused and in its original packaging.
Return procedure for SM6T56CAY:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SM6T56CAY Tags
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