Vishay General Semiconductor - Diodes Division SMBJ33CAHE3_A/H

Overview

SMBJ33CAHE3_A/H from Vishay General Semiconductor is a bidirectional surface-mount transient voltage suppressor (TVS) diode in SMB (DO-214AA) package, designed for clamping voltage transients on power and signal lines. It features a 33 V stand-off voltage (V_WM), 53.3 V maximum clamping voltage (V_C) at 11.3 A peak pulse current (I_PPM), and 600 W peak pulse power (10/1000 μs waveform), making it suitable for protecting MOSFETs, ICs, and sensor signal lines in industrial power supplies and telecom interfaces.

For engineers reviewing the SMBJ33CAHE3_A/H datasheet, SMBJ33CAHE3_A/H pinout, SMBJ33CAHE3_A/H application, or SMBJ33CAHE3_A/H equivalent, key selection criteria include bidirectional clamping capability, AEC-Q101 qualification status, thermal resistance (R_θJA = 100 °C/W), junction temperature range (–55 to +150 °C), and compliance with UL 497B surge protector classification.

Technical Context

This device operates as a voltage-clamped avalanche diode, responding within <1 ps to transient overvoltages and limiting reverse voltage across protected circuitry to ≤53.3 V under 11.3 A surge. Its bidirectional symmetry ensures identical clamping behavior in both polarities, eliminating polarity-sensitive layout constraints.

Designed for automated SMT assembly, it uses glass-passivated junction technology and matte tin-plated leads compliant with J-STD-002 and JESD 22-B102. The SMB package meets UL 94 V-0 flammability rating and MSL Level 1 per J-STD-020 (peak reflow 260 °C).

Key Specifications

Pinout & Package

Package: SMB (DO-214AA), surface-mount, bidirectional - no polarity marking; symmetrical anode/cathode terminals.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMBJ33CAHE3_A/H, SMBJ33CA-E3/52 offers identical electrical performance without AEC-Q101 validation, while SAC33CA trades surge robustness for smaller footprint-neither is pin-compatible due to differing packages (SMB vs. SOD-123FL), requiring layout revision.

Availability

SMBJ33CAHE3_A/H is available at Aetrix Electronics and suitable for industrial motor drives, telecom line interface, automotive body control modules, and consumer appliance power input requiring stable component supply and long-term lifecycle support.

Supply support for SMBJ33CAHE3_A/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, rectifiers, MOSFETs, and protection devices with emphasis on reliability, efficiency, and application-specific optimization.

The SMBJ series targets high-energy transient suppression in harsh environments, with SMBJ33CAHE3_A/H engineered specifically for bidirectional 33 V systems needing automotive-grade validation and UL recognition.

FAQ

What is the clamping voltage of SMBJ33CAHE3_A/H at its rated peak pulse current?

The SMBJ33CAHE3_A/H has a maximum clamping voltage (V_C) of 53.3 V at its rated peak pulse current (I_PPM) of 11.3 A under the standardized 10/1000 μs waveform. This value is measured per ANSI/IEEE C62.35 and defines the upper voltage limit imposed on protected circuitry during surge events. The SMBJ33CAHE3_A/H maintains this clamping performance across its full operating temperature range of –55 to +150 °C.

Is SMBJ33CAHE3_A/H suitable for automotive applications?

Yes, SMBJ33CAHE3_A/H is AEC-Q101 qualified, meaning it has passed stress tests including high-temperature reverse bias, temperature cycling, and ESD verification required for automotive electronic components. Its construction-glass-passivated junction, matte tin leads, and UL 497B recognition-supports deployment in body control modules, infotainment power rails, and sensor interfaces where reliability under thermal and mechanical stress is mandatory. The SMBJ33CAHE3_A/H meets these requirements without derating up to +125 °C ambient.

How does the bidirectional design of SMBJ33CAHE3_A/H affect circuit layout?

The SMBJ33CAHE3_A/H has no polarity marking and identical electrical characteristics in both directions, allowing placement across any two-node connection without regard to orientation. This eliminates the need for cathode-band alignment during pick-and-place and simplifies layout for AC-coupled lines, differential buses (e.g., RS-485), or floating power domains. Unlike unidirectional TVS diodes, the SMBJ33CAHE3_A/H avoids risk of incorrect installation and supports symmetric transient suppression without additional components.

What is the thermal resistance of SMBJ33CAHE3_A/H, and how does it impact PCB design?

The SMBJ33CAHE3_A/H has a typical junction-to-ambient thermal resistance (R_θJA) of 100 °C/W when mounted on 0.2" × 0.2" (5.0 mm × 5.0 mm) copper pads per terminal. This value assumes minimal copper area; increasing pad size or adding internal ground planes reduces R_θJA and improves surge endurance. For continuous power dissipation near its 5.0 W rating, thermal vias and copper pour are recommended. The SMBJ33CAHE3_A/H's R_θJA directly determines safe operating area under repetitive surge conditions.

Does SMBJ33CAHE3_A/H meet UL safety standards?

Yes, SMBJ33CAHE3_A/H is Underwriters Laboratories (UL) recognized under file E136766 for both unidirectional and bidirectional configurations, complying with UL 497B for primary protector classification. This certification validates its suitability in telecom, industrial, and building automation systems where regulatory approval for surge protection is required. The UL listing covers construction, flammability (UL 94 V-0 molding compound), and electrical performance-no additional external certification is needed when using SMBJ33CAHE3_A/H as a designated protector element.