Vishay General Semiconductor - Diodes Division SM6T24AHE3/5B

Overview

SM6T24AHE3/5B from Vishay General Semiconductor is a unidirectional transient voltage suppressor (TVS) diode in SMB (DO-214AA) package, rated for 24 V standoff voltage (VWM = 20.5 V), 33.2 V clamping voltage at 18 A peak pulse current, and 600 W peak pulse power with 10/1000 μs waveform. It features glass passivated junction, AEC-Q101 qualification, and is used to protect MOSFETs and sensor signal lines in automotive powertrain control modules.

For engineers reviewing the SM6T24AHE3/5B datasheet, SM6T24AHE3/5B pinout, SM6T24AHE3/5B application, or SM6T24AHE3/5B equivalent, key selection criteria include clamping voltage margin vs. protected IC's absolute maximum rating, I_PPM derating above 25 °C, unidirectional polarity marking, and AEC-Q101 compliance for automotive-grade deployment.

Technical Context

This TVS operates as a voltage-clamped shunt protector: under normal bias it presents <1 μA leakage at 20.5 V; during transients exceeding breakdown (V_BR = 22.8–25.2 V at 1 mA), it avalanches to clamp voltage ≤33.2 V at 18 A (10/1000 μs). Its low-inductance SMB package enables fast response (<1 ns) to ESD and load-dump surges.

Thermal design relies on R_θJA = 100 °C/W (typ.) and R_θJL = 20 °C/W (typ.), with maximum junction temperature of 150 °C. The cathode band denotes polarity, and device meets J-STD-020 MSL Level 1 (260 °C peak reflow).

Key Specifications

Pinout & Package

Package: SMB (DO-214AA), surface-mount, matte tin-plated leads, RoHS-compliant and AEC-Q101 qualified. Dimensions: 4.57 mm × 3.94 mm × 2.20 mm (L × W × H), with cathode band marking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMAJ24A-E3/5B and 1.5SMC24A, SM6T24AHE3/5B uniquely combines AEC-Q101 qualification, SMB footprint, and 600 W rating-making it the only option qualified for automotive under-hood use without sacrificing board area or surge margin.

Availability

SM6T24AHE3/5B is available at Aetrix Electronics and suitable for automotive powertrain control, industrial sensor signal protection, and telecom DC power feeds requiring stable component supply, long-term lifecycle support, and traceable AEC-Q101 qualified parts.

Supply support for SM6T24AHE3/5B 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, MOSFETs, and protection devices with emphasis on reliability, automotive qualification, and high-volume manufacturability.

The SM6T Series is designed specifically for robust transient suppression in harsh environments-including automotive, industrial, and telecom-where AEC-Q101 compliance, low clamping voltage, and 600 W surge capability are mandatory.

FAQ

What is the clamping voltage of SM6T24AHE3/5B at its rated peak pulse current?

The SM6T24AHE3/5B has a maximum clamping voltage (V_C) of 33.2 V when subjected to its rated peak pulse current of 18 A using the standard 10/1000 μs waveform. This value is measured per Figure 1 in Vishay document 88385 and defines the upper voltage limit imposed on protected circuitry during surge events. Designers must verify that this clamping level remains safely below the absolute maximum ratings of downstream components. The SM6T24AHE3/5B achieves this performance while maintaining low leakage and stable V_BR across temperature.

Is SM6T24AHE3/5B suitable for automotive applications?

Yes, SM6T24AHE3/5B is AEC-Q101 qualified and explicitly designated for automotive use, as confirmed by its "HE3" suffix and documentation in Vishay's SM6T series datasheet (Rev. 09-Jan-2024, Doc. #88385). It is rated for operation from −65 °C to +150 °C and validated for under-hood environments including engine control units and battery management systems. The SM6T24AHE3/5B meets J-STD-020 MSL Level 1 and undergoes rigorous stress testing per AEC-Q101 requirements.

What does the "HE3/5B" suffix indicate in SM6T24AHE3/5B?

The "HE3" suffix denotes RoHS-compliant construction with AEC-Q101 qualification, while "5B" specifies packaging in 13-inch diameter plastic tape and reel, with a base quantity of 3200 units. This ordering code distinguishes SM6T24AHE3/5B from non-automotive variants (e.g., E3/5B) and alternate reels (e.g., HE3/52 for 7-inch reels). The SM6T24AHE3/5B is fully traceable, whisker-tested per JESD 201 Class 2, and uses matte tin-plated leads solderable per J-STD-002.

How does SM6T24AHE3/5B differ from bidirectional TVS diodes like SM6T24CA?

SM6T24AHE3/5B is unidirectional and features a cathode band for polarity identification, intended for DC line protection where reverse voltage is blocked. In contrast, SM6T24CA is bidirectional (no polarity marking) and symmetrically clamps both positive and negative transients-used in AC-coupled or floating signal lines. Their V_BR and V_C values differ: SM6T24AHE3/5B has V_BR = 22.8–25.2 V (1 mA), while SM6T24CA has identical V_BR but dual-direction clamping. The SM6T24AHE3/5B is not interchangeable with SM6T24CA without circuit redesign.

What is the thermal resistance profile of SM6T24AHE3/5B and how does it affect PCB layout?

SM6T24AHE3/5B has typical thermal resistance R_θJA = 100 °C/W (junction-to-ambient) and R_θJL = 20 °C/W (junction-to-lead), measured on 0.2" × 0.2" copper pads per terminal. To maintain T_J ≤150 °C under 5.0 W steady-state dissipation, PCB layout must provide adequate copper area and airflow. For surge conditions, short-duration pulses minimize average heating, but repeated events require thermal derating per Figure 2 in the datasheet. The SM6T24AHE3/5B's SMB package enables compact placement near protected nodes without compromising thermal performance.