Vishay General Semiconductor - Diodes Division SMBJ45A-M3/52

Overview

SMBJ45A-M3/52 from Vishay General Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode designed for robust overvoltage protection of DC power rails and signal lines. It features a 45 V standoff voltage (V_WM), 50.0–55.3 V breakdown range (V_BR at 1.0 mA), 72.7 V maximum clamping voltage (V_C) at 8.3 A peak pulse current, and 600 W peak pulse power rating with 10/1000 µs waveform - deployed in industrial motor drives, automotive body control modules, and industrial sensor interfaces.

For engineers reviewing the SMBJ45A-M3/52 datasheet, SMBJ45A-M3/52 pinout, SMBJ45A-M3/52 application, or SMBJ45A-M3/52 equivalent, key selection criteria include unidirectional polarity, SMB (DO-214AA) package compatibility, 1.0 µA max reverse leakage at V_WM, 150 °C max junction temperature, and halogen-free RoHS-compliant construction per M3 suffix.

Technical Context

This TVS diode operates as a clamping device in parallel with protected circuitry, conducting only when transient voltage exceeds its breakdown threshold. Its glass-passivated junction ensures stable V_BR tolerance (±5% typical), low incremental surge resistance, and fast response time (<1 ns), enabling effective suppression of ESD, lightning-induced surges, and inductive switching transients.

The SMBJ45A-M3/52 is rated for 100 A non-repetitive forward surge current (I_FSM) and exhibits a positive temperature coefficient of V_BR (0.102 %/°C), supporting predictable derating across -55 °C to +150 °C operating range. Thermal resistance is 100 °C/W (junction-to-ambient) on standard 0.2" × 0.2" copper pads.

Key Specifications

Pinout & Package

Package: SMB (DO-214AA), molded plastic case with matte tin-plated leads; cathode indicated by band marking on one end; meets UL 94 V-0 flammability rating and JESD 201 Class 2 whisker resistance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMBJ45A-E3/52, the SMBJ45A-M3/52 adds halogen-free compliance without altering clamping performance; versus SMCJ45A-M3, it trades surge capacity for compact SMB packaging - making SMBJ45A-M3/52 optimal for space-constrained 48 V DC systems needing full environmental compliance.

Availability

SMBJ45A-M3/52 is available at Aetrix Electronics and suitable for industrial motor drives, automotive body control modules, and telecom power feeds requiring stable component supply, long-term lifecycle support, and halogen-free manufacturing compliance.

Supply support for SMBJ45A-M3/52 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, efficiency, and application-specific optimization.

The SMBJ series was engineered for high-reliability transient suppression in harsh environments - targeting automotive, industrial, and telecom systems where consistent clamping performance and AEC-Q101 readiness are critical.

FAQ

What is the clamping voltage of SMBJ45A-M3/52 and how is it verified?

The SMBJ45A-M3/52 has a maximum clamping voltage (V_C) of 72.7 V at 8.3 A peak pulse current with a 10/1000 µs waveform. This value is measured per ANSI/IEEE C62.35 standards and confirmed in Vishay's datasheet revision 09-Jan-2024 (Document Number: 88392). The SMBJ45A-M3/52 maintains this clamping performance across its full operating temperature range (-55 °C to +150 °C) with no derating required below 25 °C ambient.

Is SMBJ45A-M3/52 suitable for automotive applications?

SMBJ45A-M3/52 is halogen-free and RoHS-compliant but not AEC-Q101 qualified - its base ordering code lacks the "H" prefix (e.g., HM3) required for automotive qualification. For automotive use, select SMBJ45AHM3_B/H instead. The SMBJ45A-M3/52 remains appropriate for non-safety-critical automotive subsystems like infotainment power rails where AEC-Q101 is not mandated.

How does the M3 suffix differ from E3 in SMBJ45A-M3/52?

The M3 suffix indicates halogen-free, RoHS-compliant construction, whereas E3 denotes RoHS-compliant but standard brominated flame retardant molding compound. Both share identical electrical characteristics, SMB package dimensions, and thermal performance. The SMBJ45A-M3/52 meets JEDEC J-STD-020 MSL Level 1 and JESD 201 Class 2 whisker resistance, making it suitable for lead-free reflow and high-reliability deployments where halogen content must be minimized.

What is the reverse leakage current specification for SMBJ45A-M3/52 at 45 V?

The SMBJ45A-M3/52 specifies a maximum reverse leakage current (I_D) of 1.0 µA at its 45 V standoff voltage (V_WM) and 25 °C ambient temperature. This low leakage ensures minimal power loss in always-on 48 V systems and avoids loading high-impedance sensor bias networks - a critical parameter validated in Vishay's Electrical Characteristics table for all SMBJ45A variants.

Can SMBJ45A-M3/52 replace SMBJ43A-M3/52 in an existing design?

Yes, SMBJ45A-M3/52 can replace SMBJ43A-M3/52 if the system's maximum transient voltage margin allows a 2 V increase in V_WM. SMBJ43A-M3/52 has V_WM = 43 V and V_C = 69.4 V; SMBJ45A-M3/52 raises V_WM to 45 V and V_C to 72.7 V. This shift provides higher standoff headroom but slightly higher clamping - verify that protected ICs tolerate the +3.3 V clamping delta before substitution. The SMBJ45A-M3/52 retains identical SMB footprint and thermal behavior.