Vishay General Semiconductor - Diodes Division SMA6F7.5A-M3/6B

Overview

SMA6F7.5A-M3/6B from Vishay General Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode in SlimSMA (DO-221AC) package, designed for clamping inductive switching transients and ESD events on power and signal lines. It features a 7.5 V stand-off voltage (V_WM), 8.33–9.21 V breakdown voltage (V_BR at 1.0 mA), 11.8 V max clamping voltage (V_C) at 50 A (10/1000 μs), 600 W peak pulse power rating, and IEC 61000-4-2 Level 4 ESD immunity (±15 kV air / ±8 kV contact). It protects MOSFET gates, microcontroller I/O, and sensor interfaces in consumer and industrial power supplies.

For engineers reviewing the SMA6F7.5A-M3/6B datasheet, SMA6F7.5A-M3/6B pinout, SMA6F7.5A-M3/6B application, or SMA6F7.5A-M3/6B equivalent, key selection criteria include clamping voltage margin relative to protected IC V_DD, leakage current at operating bias (<50 μA at 7.5 V), thermal derating above 25 °C, and compatibility with automated SMT placement on FR4 PCBs with 2 oz copper.

Technical Context

This TVS diode operates as a voltage-clamped shunt protector: under normal bias (≤7.5 V), it draws <50 μA reverse leakage; when transient voltage exceeds ~8.33 V, it avalanches and clamps the line to ≤11.8 V at 50 A (10/1000 μs). Its low dynamic resistance (0.051 Ω) ensures rapid response and minimal overshoot during fast transients.

The device uses silicon avalanche junction technology in a SlimSMA (DO-221AC) package with matte tin-plated leads, rated for MSL Level 1 reflow (260 °C peak), and optimized for high-density layouts where height ≤0.95 mm is critical. It is not bidirectional - polarity is fixed, with cathode indicated by a band.

Key Specifications

Pinout & Package

Package: SlimSMA (DO-221AC), surface-mount, single-ended unidirectional configuration. Height ≤0.95 mm, footprint compatible with standard SMA land patterns but with reduced profile. Cathode denoted by molded band.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar transient suppression applications.

Compared with SMA6F7.5A-M3/6A, the -6B variant offers higher reel quantity for production continuity; compared with SMAJ7.5A-M3/61, it delivers 50 % higher peak power in 46 % less height - critical for modern compact power electronics where thermal mass and layout area are constrained.

Availability

SMA6F7.5A-M3/6B is available at Aetrix Electronics and suitable for USB-C PD adapters, industrial sensor nodes, automotive body control modules, and consumer appliance motor drivers requiring stable component supply and full MSL Level 1 compliance.

Supply support for SMA6F7.5A-M3/6B 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

Vishay General Semiconductor is a global leader in discrete semiconductors, specializing in diodes, rectifiers, MOSFETs, and protection devices with emphasis on reliability, efficiency, and application-specific optimization.

The SMA6F series is part of Vishay's TRANSZORB® TVS platform, engineered specifically for high-power, low-profile transient suppression in space- and performance-critical power and interface circuits.

FAQ

What is the maximum clamping voltage of the SMA6F7.5A-M3/6B under a 50 A, 10/1000 μs surge?

The SMA6F7.5A-M3/6B has a maximum clamping voltage (V_C) of 11.8 V when subjected to a 50 A, 10/1000 μs transient waveform. This value is measured per standard test conditions in the Vishay datasheet (Document Number: 89458, Rev. 17-Sep-2021) and defines the upper voltage limit imposed on the protected circuit during such an event. The SMA6F7.5A-M3/6B achieves this with low dynamic resistance (0.051 Ω), ensuring consistent clamping performance across production lots.

Is the SMA6F7.5A-M3/6B bidirectional or unidirectional?

The SMA6F7.5A-M3/6B is a unidirectional transient voltage suppressor. Its polarity is fixed, with the cathode identified by a molded band on the SlimSMA (DO-221AC) package. It conducts only during positive transients on the anode relative to cathode and must be oriented correctly in-circuit - reverse connection will not provide protection. The SMA6F7.5A-M3/6B is not rated for bidirectional operation; for symmetrical surge protection, a dedicated bidirectional TVS (e.g., SMA6F7.5CA) would be required.

Does the SMA6F7.5A-M3/6B meet RoHS and halogen-free requirements?

Yes, the SMA6F7.5A-M3/6B carries the "M3" suffix, indicating it is halogen-free, RoHS-compliant, and qualified for industrial-grade applications. Per Vishay documentation, the molding compound meets UL 94 V-0 flammability rating, and the matte tin-plated leads comply with J-STD-002 and JESD22-B102 solderability standards. The M3 designation also confirms compliance with JESD 201 Class 2 whisker testing, making the SMA6F7.5A-M3/6B suitable for long-life, thermally cycled deployments.

What is the thermal resistance junction-to-ambient (R_θJA) for the SMA6F7.5A-M3/6B on a standard FR4 PCB?

For the SMA6F7.5A-M3/6B mounted on a standard FR4 PCB with 2 oz copper and the recommended footprint, the typical junction-to-ambient thermal resistance (R_θJA) is 120 °C/W, with a maximum of 150 °C/W per JEDEC 51-2A. This value governs power derating: at ambient temperatures above 25 °C, the device's 8 W power dissipation rating must be linearly reduced. The SMA6F7.5A-M3/6B's R_θJA reflects its SlimSMA package's limited thermal mass and is consistent across the SMA6F family.

Can the SMA6F7.5A-M3/6B be used to protect a 3.3 V logic line?

No - the SMA6F7.5A-M3/6B is not suitable for direct protection of 3.3 V logic lines because its 7.5 V stand-off voltage (V_WM) exceeds typical 3.3 V rail tolerances and its 8.33 V minimum breakdown voltage risks false triggering or excessive leakage. For 3.3 V systems, a lower-voltage TVS such as SMA6F3.3A-M3/6B (V_WM = 3.3 V) is required. The SMA6F7.5A-M3/6B is intended for 5 V, 7 V, or higher rails where its V_WM provides adequate margin above nominal voltage.