Vishay General Semiconductor - Diodes Division SMBJ45AHE3_A/I

Overview

SMBJ45AHE3_A/I 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 DC power rails and signal lines. It features a 45 V stand-off voltage (V_WM), 50.0–55.3 V breakdown voltage (V_BR) at 1 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 automotive power supply inputs, industrial sensor interfaces, and telecom line protection.

For engineers reviewing the SMBJ45AHE3_A/I datasheet, SMBJ45AHE3_A/I pinout, SMBJ45AHE3_A/I application, or SMBJ45AHE3_A/I equivalent, this page delivers verified electrical parameters, AEC-Q101 qualification status, thermal resistance (R_θJA = 100 °C/W), junction temperature range (–55 to +150 °C), and RoHS-compliant packaging details essential for ESD/surge protection design-in and reliability validation.

Technical Context

The SMBJ45AHE3_A/I operates as a unidirectional avalanche diode, clamping transients above its reverse stand-off voltage while maintaining low leakage (<1.0 µA at 45 V). Its glass-passivated junction ensures stable breakdown behavior and fast response time (<1.0 ns), critical for suppressing ESD and lightning-induced surges before IC damage occurs.

Rated for 600 W peak pulse power (10/1000 µs), it sustains repetitive surge events at 0.01 % duty cycle and derates linearly above 25 °C ambient per Fig. 2. With 20 °C/W junction-to-lead thermal resistance and MSL Level 1 moisture sensitivity, it supports reflow soldering up to 260 °C peak without preconditioning.

Key Specifications

Pinout & Package

Package: SMB (DO-214AA), surface-mount, low-profile case with matte tin-plated leads compliant with J-STD-002 and JESD 22-B102. Polarity indicated by cathode band; unidirectional configuration only.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMBJ45AHM3_A/I, the SMBJ45AHE3_A/I offers identical surge performance with standard RoHS compliance; versus SMCJ45AHE3_A/I, it trades 2.5× lower surge capacity for 40 % smaller PCB area and compatibility with fine-pitch automated placement.

Availability

SMBJ45AHE3_A/I is available at Aetrix Electronics and suitable for automotive electronics, industrial sensor interfaces, and telecom power feed applications requiring stable component supply, AEC-Q101 qualification, and RoHS compliance.

Supply support for SMBJ45AHE3_A/I 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, automotive qualification, and high-volume manufacturability.

The SMBJ series is engineered for robust transient suppression in harsh environments - targeting automotive power systems, industrial controls, and infrastructure equipment where failure tolerance and long-term stability are mandatory.

FAQ

What is the maximum clamping voltage of SMBJ45AHE3_A/I under a 600 W surge?

The SMBJ45AHE3_A/I has a maximum clamping voltage (V_C) of 72.7 V at 8.3 A peak pulse current, corresponding to the 600 W 10/1000 µs waveform. This value is measured per standard test conditions (TA = 25 °C, mounted on 0.2" × 0.2" copper pads) and guarantees that protected circuitry remains below 73 V during worst-case transient events. The SMBJ45AHE3_A/I maintains this clamping performance across its full operating temperature range.

Is SMBJ45AHE3_A/I qualified for automotive applications?

Yes, SMBJ45AHE3_A/I is AEC-Q101 qualified, as confirmed by Vishay's ordering code structure ("HE3" suffix denotes RoHS-compliant AEC-Q101 grade) and documentation in the SMBJ5.0A–SMBJ188A datasheet (Rev. 09-Jan-2024, p. 1). It is rated for junction temperatures from –55 °C to +150 °C and meets MSL Level 1 reflow requirements - making SMBJ45AHE3_A/I suitable for under-hood and body-control module deployments.

What does the "_A/I" suffix mean in SMBJ45AHE3_A/I?

The "_A/I" suffix in SMBJ45AHE3_A/I indicates revision code "A" and packaging format "I", where "I" specifies 13-inch diameter plastic tape-and-reel delivery containing 3200 units. This matches Vishay's ordering information table (p. 3 of datasheet), confirming SMBJ45AHE3_A/I is a production-ready, fully traceable variant with standard commercial lead-time and logistics handling.

How does SMBJ45AHE3_A/I compare to bidirectional TVS diodes like SMBJ45CA?

SMBJ45AHE3_A/I is unidirectional and intended for DC rail protection with polarity-sensitive placement (cathode to line), whereas SMBJ45CA is bidirectional and used for AC or floating signal lines. The SMBJ45AHE3_A/I has lower leakage (<1.0 µA at 45 V) and higher I_FSM (100 A), but cannot protect symmetrical waveforms. For 48 V DC systems, SMBJ45AHE3_A/I provides superior clamping efficiency and surge margin compared to its bidirectional counterpart.

What is the thermal resistance of SMBJ45AHE3_A/I, and how does it affect PCB layout?

The SMBJ45AHE3_A/I has a typical junction-to-ambient thermal resistance (R_θJA) of 100 °C/W when mounted on minimum recommended 0.2" × 0.2" copper pads per terminal. This value assumes no additional heatsinking; designers must allocate sufficient copper area and consider airflow to maintain T_J ≤ 150 °C during repetitive surge events. Reducing pad size or omitting thermal vias increases R_θJA, risking premature thermal runaway during sustained transient activity - a key constraint in SMBJ45AHE3_A/I layout validation.