Vishay General Semiconductor - Diodes Division SMBG15A-M3/5B

Overview

SMBG15A-M3/5B from Vishay General Semiconductor is a unidirectional surface-mount Transient Voltage Suppressor (TVS) diode in SMBG (DO-215AA) package, rated for 15 V stand-off voltage (V_WM), 16.7–18.5 V breakdown voltage (V_BR at 1 mA), and 600 W peak pulse power (10/1000 µs). It clamps transients to ≤24.4 V at 24.6 A peak surge current and is AEC-Q101 qualified for automotive electronics protection.

For engineers reviewing the SMBG15A-M3/5B datasheet, SMBG15A-M3/5B pinout, SMBG15A-M3/5B application, or SMBG15A-M3/5B equivalent, this device is selected for robust ESD and surge immunity in low-voltage DC power rails, sensor interfaces, and automotive control modules where fast response (<1 ns), low clamping voltage, and halogen-free RoHS compliance are required.

Technical Context

This TVS diode operates as a unidirectional shunt protector with cathode-banded polarity. Its silicon junction is glass passivated for stable leakage and long-term reliability under repetitive surge stress. The device responds to transient overvoltages by avalanche breakdown, limiting reverse voltage across protected circuitry within nanoseconds.

Designed for surface-mount assembly on standard PCB copper pads (0.2" × 0.2"), it delivers 600 W peak pulse power per JEDEC-standard 10/1000 µs waveform at 0.01% duty cycle, with thermal resistance of 100 °C/W (junction-to-ambient) and 20 °C/W (junction-to-lead).

Key Specifications

Pinout & Package

Two-terminal unidirectional TVS diode in SMBG (DO-215AA) package. Cathode identified by molded band; anode is unmarked end. Terminals are matte tin-plated, solderable per J-STD-002 and JESD 22-B102.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMBG15A-M3/5B, SMBG15A-E3/5B lacks halogen-free compliance but offers identical surge performance for non-automotive use, while SMBG15AHM3/5B adds formal AEC-Q101 documentation coverage without altering electrical behavior-making it suitable for Tier 1 automotive BOMs demanding full qualification records.

Availability

SMBG15A-M3/5B is available at Aetrix Electronics and suitable for automotive body electronics, industrial sensor systems, and consumer power interface designs requiring stable component supply, halogen-free compliance, and AEC-Q101 reliability assurance.

Supply support for SMBG15A-M3/5B 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 high-reliability, automotive-qualified components.

The SMBG Transient Voltage Suppressor series is engineered for robust electrostatic discharge and surge immunity in harsh environments-targeting automotive, industrial, and telecom infrastructure applications where failure tolerance is critical.

FAQ

What is the clamping voltage of SMBG15A-M3/5B at its rated peak pulse current?

The SMBG15A-M3/5B has a maximum clamping voltage (V_C) of 24.4 V when subjected to its peak pulse current (I_PPM) of 24.6 A under the standard 10/1000 µs waveform. This value is measured per JEDEC test conditions and defines the upper voltage limit imposed on protected circuitry during worst-case surge events. The SMBG15A-M3/5B maintains this clamping performance across its specified operating temperature range.

Is SMBG15A-M3/5B suitable for bidirectional transient protection?

No, SMBG15A-M3/5B is a unidirectional TVS diode, indicated by the "A" suffix and cathode band marking. It conducts only in reverse bias above V_BR and blocks forward current like a standard diode. For bidirectional protection, the SMBG15CA-M3/5B variant must be used. The SMBG15A-M3/5B is not rated for symmetrical clamping in both polarities and should not be substituted in CA-suffix applications.

Does SMBG15A-M3/5B meet automotive qualification standards?

Yes, SMBG15A-M3/5B is AEC-Q101 qualified, as confirmed in the Vishay datasheet (Document Number: 88456, Revision: 09-Jan-2024). This qualification covers stress tests including temperature cycling, humidity, mechanical shock, and surge endurance-validating its suitability for automotive powertrain, body, and infotainment systems. The "M3" suffix further confirms halogen-free and RoHS compliance required by major OEMs.

What is the thermal resistance of SMBG15A-M3/5B, and how does it affect layout design?

SMBG15A-M3/5B has a typical junction-to-ambient thermal resistance (R_θJA) of 100 °C/W and junction-to-lead (R_θJL) of 20 °C/W, measured on 0.2" × 0.2" copper pads per terminal. To maintain safe junction temperatures under repetitive surges, PCB layout must provide adequate copper area and thermal vias. The SMBG15A-M3/5B's thermal performance directly impacts its ability to sustain multiple 600 W pulses without degradation.

How does the "M3" suffix in SMBG15A-M3/5B differ from "E3" or "HM3"?

The "M3" suffix indicates halogen-free, RoHS-compliant, industrial-grade construction. "E3" is RoHS-compliant but not halogen-free; "HM3" adds AEC-Q101 qualification to the halogen-free/RoHS baseline. All three share identical electrical parameters and SMBG package, but SMBG15A-M3/5B is optimized for industrial applications requiring halogen-free compliance without formal automotive qualification documentation-distinct from SMBG15AHM3/5B which carries full AEC-Q101 traceability.