STMicroelectronics SMA6T47CAY

Overview

SMA6T47CAY from STMicroelectronics is a bidirectional 600 W transient voltage suppression (TVS) diode in SMA package, designed for automotive-grade surge protection per ISO 7637-2 (Pulse 1/2a/3a/3b) and ESD immunity per ISO 10605 (±30 kV air/contact). It features 46.7 V breakdown voltage (V_BR min), 62.8 V clamping voltage (V_CL) at 9.7 A (10/1000 µs), and operates up to +150 °C junction temperature. Used in 12 V/24 V automotive power line protection.

For engineers reviewing the SMA6T47CAY datasheet, SMA6T47CAY pinout, SMA6T47CAY application, or SMA6T47CAY equivalent, key selection criteria include bidirectional clamping capability, low leakage (≤1 µA at 85 °C), AEC-Q101 qualification, IEC 61000-4-4 Level 4 compliance (4 kV), and compatibility with FR4 PCB footprints per IPC7531.

Technical Context

This device employs planar silicon avalanche technology to deliver precise, repeatable clamping during fast transients. Its bidirectional architecture enables symmetric protection on AC-coupled or floating lines without polarity constraints.

Clamping performance is defined by dynamic resistance (R_D = 1.42 Ω at 25 °C), temperature coefficient α_T = 10.1 × 10⁻⁴/°C, and junction capacitance <100 pF at 0 V - enabling high-speed response while minimizing signal distortion in CAN, LIN, and sensor interfaces.

Key Specifications

Pinout & Package

SMA6T47CAY uses a 2-terminal SMA (DO-214AC) package with cathode band marking. Terminals are non-polarized due to bidirectional construction; either terminal may serve as anode or cathode depending on transient polarity.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar bidirectional TVS diode applications.

Compared with SMA6T47AY and SMCJ47CA, SMA6T47CAY uniquely balances AEC-Q101 compliance, bidirectional symmetry, and compact SMA packaging - making it optimal for space-constrained, polarity-agnostic automotive data and power lines where 600 W surge capacity suffices.

Availability

SMA6T47CAY is available at Aetrix Electronics and suitable for automotive power line protection, CAN bus transient suppression, and engine control unit sensor interface applications requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for SMA6T47CAY 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 vertical manufacturing capabilities and broad IP portfolio.

SMA6T47CAY belongs to the SMA6TY Transil series - engineered specifically for AEC-Q101-compliant automotive surge protection, targeting ISO 7637-2 and ISO 10605 compliance in harsh under-hood and chassis-mounted electronics.

FAQ

What is the maximum clamping voltage for SMA6T47CAY under a 48 V automotive load dump event?

The maximum clamping voltage is 62.8 V at 9.7 A (10/1000 µs waveform), verified per DS6931 Rev 9. For higher-current load dump events (e.g., ISO 7637-2 Pulse 5a), V_CL scales linearly with current using dynamic resistance R_D = 1.42 Ω - e.g., at 20 A, V_CL ≈ 62.8 V + (20 − 9.7) × 1.42 ≈ 77.5 V.

Does SMA6T47CAY require orientation during PCB placement?

No - SMA6T47CAY is bidirectional and has no anode/cathode distinction in circuit function. The cathode band marking is for traceability only; both terminals behave identically during positive or negative transients. PCB layout must maintain symmetrical trace length to both pins to preserve balanced clamping.

How does SMA6T47CAY perform at elevated junction temperatures?

V_BR and V_CL increase with temperature at α_T = 10.1 × 10⁻⁴/°C. At T_j = 125 °C, V_BR rises ~10% to ~51.4 V, and V_CL increases proportionally. Leakage remains ≤1 µA up to 150 °C, confirmed per Figure 9 in DS6931.

Can SMA6T47CAY be used in 48 V mild-hybrid vehicle systems?

Yes - its 46.7 V V_BR provides adequate margin above 48 V nominal (typically 36–58 V operating range), and its 62.8 V V_CL at 9.7 A ensures downstream 65 V-rated MOSFETs and regulators remain within safe operating area. Derating is not required up to T_j = 150 °C per absolute maximum ratings table.