Vishay General Semiconductor - Diodes Division SMBJ120CAHE3_A/H

Overview

SMBJ120CAHE3_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 120 V standoff voltage (V_WM), 133–147 V breakdown range (V_BR at 1 mA), 193 A peak pulse current (I_PPM) with 10/1000 µs waveform, 600 W peak pulse power, and operates from –55 °C to +150 °C - used for protecting MOSFETs, ICs, and sensor interfaces in industrial power supplies.

For engineers reviewing the SMBJ120CAHE3_A/H datasheet, SMBJ120CAHE3_A/H pinout, SMBJ120CAHE3_A/H application, or SMBJ120CAHE3_A/H equivalent, key selection criteria include bidirectional clamping capability, AEC-Q101 qualification status, thermal resistance (R_θJA = 100 °C/W), low leakage (<1.0 µA at V_WM), and compatibility with automated SMT placement on standard PCB pad layouts.

Technical Context

This bidirectional TVS diode uses a glass-passivated silicon junction to achieve fast response time (<1 ns), low incremental surge resistance, and stable clamping under repetitive 10/1000 µs transients. Its symmetrical I-V characteristic enables protection of AC-coupled or floating signal paths without polarity concerns.

Designed for surface-mount assembly on 0.2" × 0.2" (5.0 mm × 5.0 mm) copper pads per terminal, it meets MSL Level 1 per J-STD-020 and supports peak reflow temperatures up to 260 °C. The HE3 suffix confirms RoHS compliance and AEC-Q101 qualification for automotive-grade reliability.

Key Specifications

Pinout & Package

Package: SMB (DO-214AA), surface-mount, bidirectional configuration with no polarity marking. Dimensions: 4.57 mm × 3.94 mm × 2.20 mm (L × W × H), matte tin-plated leads solderable per J-STD-002 and JESD 22-B102.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMBJ120CAHE3_A/H, SMBJ120CA-M3/52 offers identical clamping performance without automotive qualification, while SMCJ120CAHE3_A/H delivers 2.5× higher surge power in a larger package - choice depends on reliability tier and PCB area constraints.

Availability

SMBJ120CAHE3_A/H is available at Aetrix Electronics and suitable for industrial motor drives, automotive body control modules, and telecom power supplies requiring stable component supply with AEC-Q101 assurance and RoHS compliance.

Supply support for SMBJ120CAHE3_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 is engineered for high-energy transient suppression in space-constrained surface-mount applications, targeting automotive, industrial, and telecom systems where robustness and automated assembly compatibility are critical.

FAQ

What does the "CA" suffix indicate in SMBJ120CAHE3_A/H?

The "CA" suffix denotes a bidirectional configuration - meaning SMBJ120CAHE3_A/H provides symmetrical clamping for both positive and negative transients without polarity sensitivity. This differs from unidirectional variants (e.g., SMBJ120AHE3_A/H), which require correct cathode orientation and only clamp in reverse bias. Bidirectional operation makes SMBJ120CAHE3_A/H ideal for AC-coupled lines or floating references.

Is SMBJ120CAHE3_A/H qualified for automotive use?

Yes, SMBJ120CAHE3_A/H is AEC-Q101 qualified, as confirmed by the "HE3" suffix in its part number. This qualification covers stress tests including temperature cycling, humidity bias, mechanical shock, and accelerated life testing - validating its suitability for automotive body electronics, infotainment, and power distribution modules where reliability under harsh environmental conditions is mandatory.

What is the clamping voltage of SMBJ120CAHE3_A/H at its rated peak pulse current?

The clamping voltage (V_C) of SMBJ120CAHE3_A/H is 193 V when subjected to its rated peak pulse current (I_PPM) of 193 A using the standard 10/1000 µs waveform. This value represents the maximum voltage that will appear across the protected circuit during a worst-case transient event, ensuring downstream components remain within safe operating limits.

How does the thermal resistance of SMBJ120CAHE3_A/H affect its derating in real-world PCB layouts?

SMBJ120CAHE3_A/H 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. In compact layouts with limited copper area or elevated ambient temperatures, power dissipation must be derated per Figure 2 in the datasheet - for example, at 75 °C ambient, its usable pulse power drops to ~400 W to maintain T_J ≤ 150 °C.

Can SMBJ120CAHE3_A/H replace SMBJ120AHE3_A/H in an existing design?

No - SMBJ120CAHE3_A/H cannot directly replace SMBJ120AHE3_A/H without circuit review, because the former is bidirectional while the latter is unidirectional. Substituting introduces risk of unintended conduction during forward-biased conditions. If bidirectional behavior is acceptable and layout permits, verify that system-level polarity constraints and leakage tolerance align before replacement; otherwise, retain the unidirectional variant or redesign protection topology.