Vishay General Semiconductor - Diodes Division SMBJ54A-M3/5B

Overview

SMBJ54A-M3/5B from Vishay General Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode in the SMB (DO-214AA) package, designed for robust overvoltage protection of sensitive electronics. It features a 54 V stand-off voltage (V_WM), 60.0–66.3 V breakdown voltage (V_BR) at 1 mA, 87.1 V maximum clamping voltage (V_C) at 6.9 A peak pulse current, and 600 W peak pulse power rating with 10/1000 µs waveform - deployed on power rails and signal lines in industrial motor drives and automotive ECUs.

For engineers reviewing the SMBJ54A-M3/5B datasheet, SMBJ54A-M3/5B pinout, SMBJ54A-M3/5B application, or SMBJ54A-M3/5B equivalent, this page delivers verified electrical parameters, thermal derating behavior, clamping performance under surge conditions, and halogen-free RoHS-compliant sourcing status per Vishay's M3 suffix specification.

Technical Context

This TVS diode operates as a unidirectional avalanche clamp, leveraging a glass-passivated silicon junction to deliver sub-nanosecond response to transients. Its 100 °C/W junction-to-ambient thermal resistance (R_θJA) and 20 °C/W junction-to-lead (R_θJL) define PCB pad layout requirements for sustained 5.0 W power dissipation at 50 °C ambient.

The device meets J-STD-020 MSL Level 1 moisture sensitivity and supports reflow up to 260 °C peak. With 1.0 µA max reverse leakage at V_WM = 54 V and 0.104 %/°C V_BR temperature coefficient, it maintains stable clamping across -55 °C to +150 °C operating junction range.

Key Specifications

Pinout & Package

Package: SMB (DO-214AA), surface-mount, cathode-banded unidirectional configuration. Matte tin-plated leads, compliant with J-STD-002 and JESD 22-B102 solderability standards.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMBJ54A-M3/5B, the E3 variant offers identical protection performance at lower material cost but lacks halogen-free certification, while the HM3_B/I variant adds AEC-Q101 qualification and larger reel quantity - making SMBJ54A-M3/5B the optimal balance of environmental compliance, commercial availability, and standard packaging for industrial applications.

Availability

SMBJ54A-M3/5B is available at Aetrix Electronics and suitable for industrial motor drives, automotive engine control units, telecom power rectification, and industrial PLC analog inputs requiring stable component supply with halogen-free compliance and MSL Level 1 assembly support.

Supply support for SMBJ54A-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, and protection devices with emphasis on reliability, surge robustness, and application-specific qualification.

The SMBJ series was engineered for high-energy transient suppression in harsh environments - targeting industrial automation, automotive subsystems, and telecom infrastructure where consistent clamping and long-term stability are critical.

FAQ

What is the maximum clamping voltage of SMBJ54A-M3/5B under a 10/1000 µs surge?

The SMBJ54A-M3/5B exhibits a maximum clamping voltage (V_C) of 87.1 V when subjected to its rated peak pulse current of 6.9 A using the standardized 10/1000 µs waveform. This value is measured per Figure 1 in Vishay document 88392 and defines the upper voltage limit imposed on protected circuits during surge events. The SMBJ54A-M3/5B maintains this clamping performance across its specified operating temperature range.

Does SMBJ54A-M3/5B meet automotive qualification standards?

No, SMBJ54A-M3/5B is a commercial-grade, halogen-free, RoHS-compliant device but is not AEC-Q101 qualified. For automotive applications requiring qualification, Vishay offers the SMBJ54AHM3_B/I variant, which carries the HM3 suffix and explicit AEC-Q101 certification. The SMBJ54A-M3/5B remains suitable for industrial and telecom use cases where AEC-Q101 is not mandated.

What does the "M3" suffix indicate in SMBJ54A-M3/5B?

The "M3" suffix in SMBJ54A-M3/5B denotes halogen-free, RoHS-compliant construction meeting JEDEC J-STD-020 MSL Level 1 and JESD 201 Class 2 whisker resistance requirements. It distinguishes the part from the E3 variant (RoHS-compliant but not halogen-free) and confirms compliance with environmental regulations for industrial and consumer electronics. The SMBJ54A-M3/5B uses matte tin-plated leads and UL 94 V-0 molding compound.

How is the polarity marked on SMBJ54A-M3/5B?

SMBJ54A-M3/5B is a unidirectional TVS diode with cathode indicated by a visible band on the SMB (DO-214AA) package body. The banded end corresponds to the cathode terminal, which must be connected toward the line being protected (e.g., 54 V rail), while the anode connects to ground or the reference node. No marking is used for bidirectional variants, but SMBJ54A-M3/5B is strictly unidirectional per its "A" suffix and datasheet designation.

What thermal derating applies to SMBJ54A-M3/5B above 25 °C ambient?

SMBJ54A-M3/5B follows Vishay's standard derating curve (Figure 2 in document 88392): its peak pulse power capability decreases linearly above 25 °C ambient, reaching ~50 % of 600 W at 100 °C case temperature. Continuous power dissipation (P_D = 5.0 W) is rated at T_A = 50 °C on infinite heatsink; actual PCB layout with 0.2" × 0.2" copper pads per terminal yields R_θJA ≈ 100 °C/W. Thermal design must ensure T_J ≤ 150 °C under worst-case surge repetition.