STMicroelectronics SM6T47CAY

Overview

SM6T47CAY from STMicroelectronics is a bidirectional automotive-grade Transient Voltage Suppressor (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 immunity per ISO 10605 (±30 kV air/contact discharge). It features 46.7 V minimum breakdown voltage (V_BR), 64.5 V maximum clamping voltage (V_CL) at 9.7 A (10/1000 µs), 600 W peak pulse power, and operates up to 150 °C junction temperature.

For engineers reviewing the SM6T47CAY datasheet, SM6T47CAY pinout, SM6T47CAY application, or SM6T47CAY equivalent, this device is selected for robust front-end surge suppression in 12 V automotive power networks-especially in body control modules, infotainment power rails, and sensor interface circuits where low leakage (<1 µA at 85 °C) and high thermal stability are critical.

Technical Context

The SM6T47CAY employs planar silicon technology to achieve low dynamic resistance (R_D = 0.728 Ω) and stable V_BR temperature coefficient (α_T = 10.1 × 10⁻⁴/°C), enabling predictable clamping across −55 °C to +150 °C operating range. Its bidirectional symmetry ensures identical surge response for positive and negative transients without polarity dependency.

It complies with AEC-Q101 stress testing and meets IEC 61000-4-4 Level 4 (±4 kV), ISO 10605 (±30 kV), and ISO 7637-2 Pulse 1/2a/3a/3b waveforms-making it suitable for direct placement on battery-fed lines in passenger vehicle ECUs where failure modes must be mitigated before downstream regulators or microcontrollers.

Key Specifications

Pinout & Package

SM6T47CAY is housed in an SMB (DO-214AA) surface-mount package with two terminals: Cathode (K) and Anode (A). The bidirectional configuration means both terminals function symmetrically as either cathode or anode depending on transient polarity-no polarity marking required beyond standard SMB orientation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMAJ48CA and 1.5KE47CA, SM6T47CAY delivers optimal balance of AEC-Q101 compliance, SMB footprint efficiency, and precise 46.7–49.0 V V_BR targeting 12 V automotive systems-enabling tighter clamping margins and seamless integration into high-density ECU layouts.

Availability

SM6T47CAY is available at Aetrix Electronics and suitable for automotive body electronics, infotainment power management, and ADAS camera protection requiring stable component supply across multi-year production cycles.

Supply support for SM6T47CAY 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 specializing in automotive, industrial, and power management solutions, with broad portfolio coverage from discrete protection devices to full-system MCUs.

SM6T47CAY belongs to the SM6TY series-a family of AEC-Q101-qualified, planar TVS diodes engineered specifically for ISO 7637-2 and ISO 10605 compliance in 12 V automotive electrical architectures.

FAQ

What is the maximum clamping voltage of SM6T47CAY under ISO 7637-2 Pulse 1 conditions?

The SM6T47CAY clamps to ≤64.5 V at 9.7 A (10/1000 µs), which directly covers ISO 7637-2 Pulse 1 (−150 V, 50 Ω source impedance) when applied to a 12 V system. Measured V_CL remains within specification even at T_j = 150 °C due to its low α_T (10.1 × 10⁻⁴/°C) and stable R_D.

Can SM6T47CAY replace unidirectional TVS diodes in existing designs?

No-SM6T47CAY is strictly bidirectional and lacks polarity-specific anode/cathode designation. Replacing a unidirectional TVS (e.g., SM6T47AY) requires verifying circuit topology: bidirectional use is valid only where transients occur on both polarities (e.g., AC-coupled lines or floating supplies); DC-biased rails may require unidirectional parts to avoid reverse leakage paths.

How does the SMB package affect thermal performance compared to SMA?

The SMB package (JEDEC DO-214AA) offers 20% smaller footprint than SMA (DO-214AC) but achieves comparable thermal resistance (R_th(j-a) ≈ 120 °C/W on 1 cm² Cu) when using ST's recommended 1.62 mm × 5.84 mm pads. Its lower mass enables faster reflow profiling per J-STD-020 MSL Level 1, reducing assembly risk.

Is SM6T47CAY compliant with lead-free soldering standards?

Yes-SM6T47CAY features matte tin-plated leads compliant with J-STD-002, JESD 22-B102 E3, and IPC7531, and supports peak reflow temperatures up to 245 °C (per ST's recommended profile). It meets RoHS Directive 2011/65/EU and is rated MSL Level 1 with unlimited floor life when sealed.