Vishay General Semiconductor - Diodes Division SMBJ54AHM3_B/H

Overview

SMBJ54AHM3_B/H 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 standoff voltage (V_WM), 60.0–66.3 V breakdown voltage (V_BR) at 1 mA, 600 W peak pulse power (10/1000 µs), and clamps transients to ≤87.1 V at 6.9 A peak surge current - deployed on power rails and signal lines in industrial motor drives and automotive ECUs.

For engineers reviewing the SMBJ54AHM3_B/H datasheet, SMBJ54AHM3_B/H pinout, SMBJ54AHM3_B/H application, or SMBJ54AHM3_B/H equivalent, this page delivers verified electrical parameters, thermal derating behavior, AEC-Q101 qualification status, and real-world clamping performance data critical for ESD and lightning surge protection design validation.

Technical Context

This TVS diode operates as a unidirectional avalanche clamp, leveraging glass-passivated junction technology for stable reverse-biased transient suppression. Its 100 °C/W junction-to-ambient thermal resistance (R_θJA) and 20 °C/W junction-to-lead (R_θJL) define thermal limits under repetitive surge conditions, with derating required above 25 °C ambient per Figure 2.

The device responds in <1 ps to fast-rising transients and maintains ≤1.0 µA reverse leakage at 54 V (V_WM). It meets MSL Level 1 per J-STD-020, supports 260 °C lead-free reflow, and is halogen-free and RoHS-compliant per base suffix "HM3".

Key Specifications

Pinout & Package

Package: SMB (DO-214AA), surface-mount, unidirectional polarity marked by cathode band. Dimensions: 4.57 mm × 3.94 mm × 2.20 mm (L × W × H), with matte tin-plated leads solderable per J-STD-002.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMBJ54AHM3_B/H, SMBJ54AHE3_B/H offers identical clamping and standoff but lacks halogen-free certification and automotive qualification, while SMAJ54A-M3/5B trades 33 % lower surge power and inferior thermal performance for reduced PCB area - making SMBJ54AHM3_B/H the optimal choice for AEC-Q101-compliant, high-energy industrial and automotive systems.

Availability

SMBJ54AHM3_B/H is available at Aetrix Electronics and suitable for automotive ECU designs, industrial PLC I/O modules, telecom power supplies, and MOSFET gate protection circuits requiring stable component supply with full traceability and long-term lifecycle support.

Supply support for SMBJ54AHM3_B/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 diodes, MOSFETs, optoelectronics, and passive components with emphasis on reliability, power efficiency, and automotive-grade qualification.

The SMBJ series was developed specifically for high-energy transient suppression in harsh environments, targeting automotive, industrial, and telecom applications where AEC-Q101 compliance, 600 W surge capability, and low clamping ratios are mandatory.

FAQ

What is the maximum clamping voltage of SMBJ54AHM3_B/H at its rated peak pulse current?

The SMBJ54AHM3_B/H clamps to a maximum of 87.1 V when subjected to its rated peak pulse current of 6.9 A (10/1000 µs waveform). This value is measured under standard test conditions (T_A = 25 °C, mounted on 5.0 mm × 5.0 mm copper pads) and represents the worst-case voltage seen by downstream components during surge events - critical for verifying compatibility with 100 V-rated MOSFETs or DC-DC controllers in the protected circuit.

Is SMBJ54AHM3_B/H qualified for automotive applications?

Yes, SMBJ54AHM3_B/H is AEC-Q101 qualified, as confirmed by Vishay's ordering code structure ("HM3" suffix denotes halogen-free, RoHS-compliant, and AEC-Q101-qualified variants). This qualification covers stress tests including HTGB, HTRB, TCT, and mechanical shock, validating its use in engine control units, body control modules, and ADAS power domains where reliability under thermal cycling and vibration is essential.

What does the "HM3" suffix indicate in SMBJ54AHM3_B/H?

The "HM3" suffix in SMBJ54AHM3_B/H specifies halogen-free, RoHS-compliant construction with AEC-Q101 qualification. It distinguishes the part from "E3" (RoHS-compliant only) and "HE3" (RoHS + AEC-Q101, but not halogen-free) variants. The "B/H" denotes packaging: 7″ tape-and-reel, 750 units per reel, with "B" indicating standard reel orientation and "H" the preferred package code per Vishay's ordering matrix.

How does SMBJ54AHM3_B/H compare to bidirectional TVS diodes like SMBJ54CA?

SMBJ54AHM3_B/H is unidirectional and intended for DC-coupled lines with defined polarity (e.g., 54 V supply rails), whereas SMBJ54CA is bidirectional and suited for AC or differential signal lines like RS-485 or CAN. The unidirectional SMBJ54AHM3_B/H provides lower leakage (<1.0 µA at 54 V) and higher surge current capability in one polarity, while SMBJ54CA exhibits symmetrical clamping in both directions but with doubled leakage limits for V_WM ≤10 V - making SMBJ54AHM3_B/H preferable for precision DC protection.

What is the thermal resistance profile of SMBJ54AHM3_B/H, and how does it affect layout?

SMBJ54AHM3_B/H has a typical junction-to-ambient thermal resistance (R_θJA) of 100 °C/W and junction-to-lead (R_θJL) of 20 °C/W. To maintain reliability under repetitive surges, PCB layout must use minimum 5.0 mm × 5.0 mm copper pads per terminal (per Vishay's datasheet note), and thermal vias should be added beneath the pad to inner ground planes. Without adequate copper area, junction temperature rise may exceed 150 °C during sustained surge duty cycles, risking parametric shift or failure.