My Inquiry
My Account
STMicroelectronics SM4T10CAY
- Part No.:
- SM4T10CAY
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SM4T10CAY.pdf
- Description:
- TVS DIODE 8.5VWM 19.5VC SMA
- Quantity:
- Payment:
- Shipping:
Inventory:5,000
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SM4T10CAY from STMicroelectronics is a bidirectional automotive-grade transient voltage suppression (TVS) diode in SMA package, designed for ISO 7637-2 pulse protection (Pulse 1: −150 V; Pulse 2a: +112 V; Pulse 3a: −200 V; Pulse 3b: +150 V) and ISO 10605 ESD immunity (±30 kV air/contact). It features 10 V stand-off voltage (VRM), 14.4 V clamping voltage (VCL) at 27.7 A (10/1000 µs), and 19.5 A peak pulse current (IPP) at 8/20 µs, operating up to 150 °C junction temperature.
For engineers reviewing the SM4T10CAY datasheet, SM4T10CAY pinout, SM4T10CAY application, or SM4T10CAY equivalent, this device is selected for high-reliability 12 V automotive power line surge protection where low leakage (<1 µA at 85 °C), AEC-Q101 qualification, and stable clamping under repeated transients are critical design requirements.
Technical Context
The SM4T10CAY implements a planar silicon junction structure optimized for low dynamic resistance (RD = 0.145 Ω at 25 °C) and minimal capacitance drift across temperature. Its bidirectional configuration enables symmetrical clamping on both polarities without external polarity management.
It meets stringent automotive surge standards: ISO 7637-2 Pulse 1 (inductive load dump), Pulse 2a (battery disconnection), and Pulses 3a/3b (switching transients), with validated clamping performance up to 150 °C junction temperature and <0.2 µA leakage at 25 °C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Stand-off Voltage (VRM) | 10 V - Maximum continuous reverse operating voltage before significant conduction begins; defines circuit operating margin below clamping threshold. |
| Clamping Voltage (VCL) | 14.4 V at 27.7 A (10/1000 µs) - Peak voltage seen by protected IC during worst-case surge; ensures downstream 12 V logic remains within safe absolute maximum ratings. |
| Peak Pulse Power (PPP) | 400 W (10/1000 µs) - Sustained energy-handling capability for long-duration transients like load dump; derates linearly above 25 °C ambient. |
| Leakage Current (IRM) | 1 µA max at 85 °C - Minimal standby current draw in battery-sensitive systems; avoids parasitic drain in always-on vehicle modules. |
| Junction Temperature (Tj) | −55 to +150 °C - Enables placement near hot engine-control units or power electronics without thermal derating loss. |
| ESD Rating | ±30 kV (ISO 10605, 150 pF/330 Ω & 330 pF/330 Ω) - Full-system ESD robustness without additional discrete protection layers. |
| Dynamic Resistance (RD) | 0.145 Ω at 25 °C - Low impedance limits voltage overshoot during fast-rising transients (e.g., 8/20 µs), improving clamping precision. |
Pinout & Package
SM4T10CAY is housed in an industry-standard SMA (DO-214AC) surface-mount package per JEDEC outline, with two terminals: Cathode (K) and Anode (A). The bidirectional configuration means both terminals function symmetrically as clamping nodes-no polarity orientation required during PCB layout.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (A) | Transient return path (bidirectional) | Connects to protected line; conducts surge current equally in either polarity relative to cathode. |
| Cathode (K) | Transient return path (bidirectional) | Connects to ground or reference rail; completes low-impedance path for bidirectional clamping action. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive underhood environments including thermal cycling, humidity, and mechanical shock per JESD22-A108. |
| Bidirectional clamping | Eliminates need for polarity-aware layout or dual-diode configurations; simplifies PCB routing for differential or AC-coupled lines. |
| Low dynamic resistance (0.145 Ω) | Reduces clamping voltage overshoot during fast transients, preserving margin for 12 V microcontrollers and CAN transceivers. |
| UL94 V0 resin housing | Meets flammability safety requirement for enclosed automotive modules and junction boxes. |
| Planar junction technology | Enables stable leakage (<1 µA at 85 °C) and predictable TCR over lifetime, supporting >15-year reliability in telematics and ADAS ECUs. |
Applications
| Engine Control Unit (ECU) Power Input | Body Control Module (BCM) LIN Bus Line |
|---|---|
|
Use Scenario: Protects 12 V supply input of gasoline/diesel engine control units against load dump (ISO 7637-2 Pulse 1, −150 V) and alternator switching spikes. IC Role / Device Role / Timing Role: Primary front-end TVS clamp absorbing multi-hundred-watt surges before they reach DC-DC converters and MCU power rails. Use Value: Prevents latch-up or permanent damage to 5 V/3.3 V regulators and microcontrollers during cold-cranking and battery disconnect events. |
Use Scenario: Shields LIN physical layer transceivers from ESD and board-level switching noise in door modules and seat controllers. IC Role / Device Role / Timing Role: Bidirectional line protector placed directly at connector interface to suppress ±30 kV contact discharge per ISO 10605. Use Value: Maintains LIN signal integrity (20 kbps) without adding propagation delay or capacitive loading beyond 100 pF at 0 V bias. |
| Advanced Driver Assistance Systems (ADAS) Camera Power | Electric Power Steering (EPS) Motor Driver Interface |
|
Use Scenario: Safeguards 12 V camera module power input in rear-view and surround-view systems exposed to ignition noise and harness coupling. IC Role / Device Role / Timing Role: Fast-response clamping element placed upstream of buck converter, limiting transient voltage to ≤14.4 V during 8/20 µs pulses. Use Value: Ensures uninterrupted image sensor operation during vehicle start-stop cycles and prevents pixel corruption caused by supply rail sag. |
Use Scenario: Protects H-bridge gate driver inputs and feedback sensing lines in EPS motor control units from inductive kickback during PWM commutation. IC Role / Device Role / Timing Role: Secondary-level TVS on low-voltage control signals (e.g., PWM enable, fault reporting) referenced to chassis ground. Use Value: Avoids false fault triggering and MOSFET shoot-through by clamping transients to <15 V before reaching isolated gate drivers. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar bidirectional automotive TVS applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ10CA | Same SMA package, but rated for 400 W (10/1000 µs); VCL = 17.0 V at 23.5 A - 2.6 V higher than SM4T10CAY's 14.4 V. | Higher clamping voltage reduces margin for 12 V logic; suitable only where protected ICs tolerate ≥17 V transient exposure. | Select when cost sensitivity outweighs clamping precision, and downstream components have wider VCC tolerance. |
| 1.5SMC10CA | Higher power rating (1500 W), DO-214AB package; VCL = 17.0 V at 88.2 A (10/1000 µs); larger footprint and thermal mass. | Over-specified for typical 12 V ECU inputs; requires more PCB area and may not fit space-constrained ADAS camera modules. | Prefer for high-energy industrial 24 V systems; avoid in automotive where AEC-Q101 compliance and compact SMA are mandatory. |
Compared with SMAJ10CA and 1.5SMC10CA, SM4T10CAY delivers tighter clamping (14.4 V vs. 17.0 V), lower leakage (<1 µA at 85 °C), and guaranteed AEC-Q101 qualification - making it optimal for space-constrained, thermally demanding automotive ECUs where voltage margin and long-term reliability are non-negotiable.
Availability
SM4T10CAY is available at Aetrix Electronics and suitable for engine control units, body control modules, ADAS camera power supplies, and electric power steering interfaces requiring stable component supply across automotive production lifecycles.
Supply support for SM4T10CAY 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 solutions with over 40 years of analog and protection device expertise.
The SM4Txx series belongs to ST's automotive-qualified TVS portfolio, engineered specifically for ISO 7637-2 and ISO 10605 compliance in 12 V vehicle networks - emphasizing low clamping, high temperature stability, and AEC-Q101 reliability.
FAQ
Is SM4T10CAY unidirectional or bidirectional?
SM4T10CAY is a bidirectional TVS diode, indicated by the "C" in its part number suffix. It provides symmetrical clamping for both positive and negative transients without polarity constraints, making it ideal for AC-coupled lines or floating references in automotive networks.
What is the maximum clamping voltage under 8/20 µs surge conditions?
At 19.5 A peak pulse current (IPP) with an 8/20 µs waveform, SM4T10CAY clamps to 19.5 V. This value is derived from its specified dynamic resistance (0.145 Ω) and breakdown voltage (9.9 V typ.), ensuring predictable overvoltage limiting during fast-rising transients.
Does SM4T10CAY meet AEC-Q101 requirements?
Yes - SM4T10CAY is fully AEC-Q101 qualified, having passed stress tests including high-temperature operating life (HTOL), temperature cycling, and ESD robustness per automotive qualification standards. Certification documentation is available through ST's official product page and Digi-Key/Mouser parametric filters.
Can SM4T10CAY replace SM4T10AY in a design?
No - SM4T10AY is unidirectional (anode-to-cathode only), while SM4T10CAY is bidirectional. Substitution requires verifying circuit polarity: if the protected line is referenced to ground and only sees positive transients, SM4T10AY may be used; otherwise, SM4T10CAY is mandatory for full bidirectional protection.
SM4T10CAY Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- DO-214AC, SMA
- Series:
- SM4TY, TRANSIL™
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- -
- Bidirectional Channels:
- 1
- Voltage - Reverse Standoff (Typ):
- 8.5V
- Voltage - Breakdown (Min):
- 9.4V
- Voltage - Clamping (Max) @ Ipp:
- 19.5V
- Current - Peak Pulse (10/1000µs):
- 124A (8/20µs)
- Power - Peak Pulse:
- 400W
- 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:
- DO-214AC (SMA)
SM4T10CAY FAQ
1.How can I place an order for SM4T10CAY through Aetrix?
Please submit a Request for Quotation (RFQ) for SM4T10CAY 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 SM4T10CAY reliable?
The price and inventory of SM4T10CAY are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SM4T10CAY is usually 5 days.
3.What payment methods are accepted for SM4T10CAY?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM4T10CAY transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SM4T10CAY?
SM4T10CAY orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SM4T10CAY 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 SM4T10CAY?
For technical support, including SM4T10CAY datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM4T10CAY requirements.
6.How does Aetrix verify that SM4T10CAY is sourced from the original manufacturer or authorized distributors?
All SM4T10CAY 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 SM4T10CAY meets industry standards.
7.What is the process for return or replacement of SM4T10CAY?
All SM4T10CAY units undergo pre-shipment inspection (PSI). If there is an issue with SM4T10CAY, 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 SM4T10CAY part is unused and in its original packaging.
Return procedure for SM4T10CAY:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SM4T10CAY Tags
-
ESD9B5.0ST5G
onsemi
-
DESD3V3E1BL-7B
Diodes Incorporated
-
ESD5Z3.3T1G
onsemi
-
D5V0H1B2LP-7B
Diodes Incorporated
-
D5V0P1B2LP-7B
Diodes Incorporated
-
DESD5V0U1BA-7
Diodes Incorporated
-
ESD5Z5.0T1G
onsemi
-
DESD5V0U1BB-7
Diodes Incorporated
-
D12V0L1B2LP-7B
Diodes Incorporated
-
PESD2V0Y1BSFYL
Nexperia USA Inc.
-
DF2S5M4CT,L3F
Toshiba Semiconductor and Storage
-
D5V0L1B2WS-7
Diodes Incorporated
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
