Vishay General Semiconductor - Diodes Division SMBJ24CAHE3_A/I

Overview

SMBJ24CAHE3_A/I 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 signal or power lines. It features a 24 V standoff voltage (V_WM), 38.9 V maximum clamping voltage (V_C) at 15.4 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 and telecom equipment.

For engineers reviewing the SMBJ24CAHE3_A/I datasheet, SMBJ24CAHE3_A/I pinout, SMBJ24CAHE3_A/I application, or SMBJ24CAHE3_A/I equivalent, key selection criteria include bidirectional surge suppression capability, AEC-Q101 qualification status, clamping performance under 10/1000 µs transients, thermal resistance (R_θJA = 100 °C/W), and RoHS-compliant, halogen-free construction with matte tin-plated leads.

Technical Context

This device operates as a voltage-clamping protector with symmetrical breakdown behavior in both directions due to its bidirectional construction. Its glass-passivated junction ensures stable avalanche characteristics and low incremental surge resistance, enabling fast response (<1 ps) to ESD and lightning-induced transients.

The SMBJ24CAHE3_A/I is rated for repetitive 10/1000 µs surges at 0.01% duty cycle and derates linearly above 25 °C ambient per Figure 2. It meets MSL Level 1 per J-STD-020, with maximum reflow peak temperature of 260 °C, and supports automated SMT placement without lead damage risk.

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), with matte tin-plated leads compliant to J-STD-002 and JESD 22-B102.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMBJ24CAHE3_A/I, the SMBJ24CA-E3/52 offers identical clamping and surge ratings at lower cost but lacks automotive qualification and halogen-free compliance; the SMCJ24CAHE3_A/I provides 2.5× higher pulse power and superior thermal management at the expense of board space and unit price.

Availability

SMBJ24CAHE3_A/I is available at Aetrix Electronics and suitable for industrial motor drives, automotive sensor interfaces, telecom power inputs, and consumer USB-C port protection requiring stable component supply across long-lifecycle programs.

Supply support for SMBJ24CAHE3_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, 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 SMT applications, targeting automotive, industrial, and communications systems where AEC-Q101 compliance and consistent clamping performance are critical.

FAQ

What does the "CA" suffix indicate in SMBJ24CAHE3_A/I?

The "CA" suffix denotes a bidirectional configuration, meaning SMBJ24CAHE3_A/I provides symmetrical transient suppression for both positive and negative voltage excursions. Unlike unidirectional variants (e.g., SMBJ24A), it has no cathode marking and delivers identical V_BR, V_C, and I_PPM in either polarity - essential for AC-coupled or floating signal lines such as RS-485 or CAN FD buses.

Is SMBJ24CAHE3_A/I suitable for automotive applications?

Yes, SMBJ24CAHE3_A/I is AEC-Q101 qualified and manufactured with halogen-free, RoHS-compliant materials. Its qualification covers temperature cycling, highly accelerated life testing (HALT), and ESD robustness - making it appropriate for under-hood and cabin applications including ADAS camera modules, body control units, and infotainment power supplies where transient immunity and long-term reliability are mandatory.

How does the clamping voltage of SMBJ24CAHE3_A/I compare to its standoff voltage?

SMBJ24CAHE3_A/I has a 24 V standoff voltage (V_WM) and a maximum clamping voltage (V_C) of 38.9 V at 15.4 A. This 14.9 V differential represents the worst-case voltage overshoot imposed on protected circuitry during a full-rated 600 W transient. The ratio V_C/V_WM = 1.62 reflects efficient avalanche energy absorption - lower than typical for 600 W TVS diodes, indicating strong clamping capability for sensitive 24 V logic and analog circuits.

What is the thermal resistance of SMBJ24CAHE3_A/I, and how does it affect PCB layout?

SMBJ24CAHE3_A/I 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. To maintain T_J ≤ 150 °C under 5.0 W steady-state dissipation (P_D), ambient must stay below 100 °C - or additional copper area, internal planes, or thermal vias must be added. For pulsed operation, thermal mass dominates, so pad size is less critical than for continuous loads.

Can SMBJ24CAHE3_A/I replace SMBJ24A in an existing design?

No - SMBJ24CAHE3_A/I is bidirectional, while SMBJ24A is unidirectional with a marked cathode band. Substituting them without verifying circuit topology may cause unintended conduction or failure to clamp negative transients. If the original design uses SMBJ24A on a DC rail with defined polarity, SMBJ24CAHE3_A/I will conduct continuously in reverse bias unless the line is truly floating or AC-coupled. Always validate polarity and grounding scheme before replacement.