Vishay General Semiconductor - Diodes Division SMBJ43D-M3/H

Overview

SMBJ43D-M3/H from Vishay General Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode in SMB (DO-214AA) package, designed for robust overvoltage protection of DC power rails and signal lines. It features a 43 V stand-off voltage (VWM), 48.5–52.1 V breakdown voltage (VBR) at 1 mA, 68.5 V maximum clamping voltage (VC) at 8.76 A peak pulse current, and 600 W peak pulse power rating with 10/1000 μs waveform.

For engineers reviewing the SMBJ43D-M3/H datasheet, SMBJ43D-M3/H pinout, SMBJ43D-M3/H application, or SMBJ43D-M3/H equivalent, this device is selected for high-reliability surge suppression in industrial power supplies, automotive ECUs, sensor interfaces, and telecom line cards where tight VBR tolerance (±3.5 %), low leakage (<0.5 μA at VWM), and MSL Level 1 moisture sensitivity are critical.

Technical Context

This TVS diode operates as a unidirectional clamping device, conducting only during reverse-voltage transients above its breakdown threshold while remaining highly resistive below 43 V. Its silicon avalanche structure delivers sub-nanosecond response time and low incremental surge resistance to limit transient energy effectively.

The SMBJ43D-M3/H is rated for 150 °C maximum junction temperature, 125 °C/W junction-to-ambient thermal resistance on minimum pad layout, and complies with UL 497B recognition (QVGQ2) for protector classification. It is halogen-free, RoHS-compliant, and passes JESD 201 Class 2 whisker testing.

Key Specifications

Pinout & Package

Package: SMB (DO-214AA), molded plastic case with matte tin-plated leads, UL 94 V-0 rated compound, cathode indicated by band on one end.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMAJ43A and SMCJ43A, SMBJ43D-M3/H offers optimal balance of 600 W surge capability, compact SMB footprint, and ±3.5 % VBR tolerance-making it preferred for space-constrained industrial and automotive modules requiring precise, repeatable clamping behavior without layout redesign.

Availability

SMBJ43D-M3/H is available at Aetrix Electronics and suitable for industrial power supplies, automotive body control units, telecom line cards, and sensor interface circuits requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for SMBJ43D-M3/H 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 high-reliability diodes, MOSFETs, optoelectronics, and passive components for demanding industrial, automotive, and computing applications.

The SMBJ series is part of Vishay's TRANSZORB® TVS platform, engineered specifically for fast, repeatable transient suppression in surface-mount power and signal line protection across harsh environments.

FAQ

What is the clamping voltage of SMBJ43D-M3/H at its rated peak pulse current?

The SMBJ43D-M3/H has a maximum clamping voltage (VC) of 68.5 V at 8.76 A peak pulse current (IPPM), measured using a 10/1000 μs waveform. This value defines the highest voltage that will appear across the protected circuit during a standardized surge event, ensuring downstream components remain within safe operating limits. The SMBJ43D-M3/H maintains this clamping performance consistently due to its low incremental surge resistance and tightly controlled avalanche characteristics.

Is SMBJ43D-M3/H suitable for bidirectional transient protection?

No, SMBJ43D-M3/H is a unidirectional TVS diode, indicated by the absence of "C" in its part number (e.g., SMBJ43CD would be bidirectional). It conducts only in reverse bias above VBR and must be oriented with the cathode band toward the protected line. For bidirectional AC or symmetrical signal line protection, Vishay's SMBJ43CD variant is required-its electrical characteristics apply equally in both directions, unlike the SMBJ43D-M3/H.

What does the "-M3/H" suffix signify in SMBJ43D-M3/H?

The "-M3" suffix denotes halogen-free, RoHS-compliant construction meeting JESD 201 Class 2 whisker resistance, while "/H" specifies packaging in 7″ diameter plastic tape and reel with 750 units per reel. This configuration ensures compatibility with high-speed pick-and-place equipment and satisfies environmental compliance requirements for industrial and automotive manufacturing. The SMBJ43D-M3/H is not offered in bulk or tube formats under this ordering code.

How does SMBJ43D-M3/H perform under elevated ambient temperatures?

The SMBJ43D-M3/H derates linearly above 25 °C ambient: its 1.0 W power dissipation drops to zero at 150 °C junction temperature. At 85 °C ambient, maximum steady-state power falls to ~0.5 W, but its 600 W peak pulse rating remains valid for short-duration transients (≤50 ms) per Fig. 2 in the datasheet. Thermal design must use RθJA = 125 °C/W (minimum pad layout) to ensure TJ stays within 150 °C during surge events.

Can SMBJ43D-M3/H replace older SMBJ43A devices in existing designs?

Yes, SMBJ43D-M3/H is a direct functional and mechanical replacement for legacy SMBJ43A parts, sharing identical SMB (DO-214AA) package dimensions, pinout, and key electrical parameters (VWM = 43 V, VC = 68.5 V). The "D" suffix indicates updated process control yielding tighter VBR tolerance (±3.5 % vs. older ±5 %), and "M3" confirms halogen-free/RoHS compliance. No PCB or schematic changes are needed when upgrading to SMBJ43D-M3/H.