Vishay General Semiconductor - Diodes Division SMCJ64CAHM3_A/I

Overview

SMCJ64CAHM3_A/I from Vishay General Semiconductor is a bidirectional transient voltage suppressor (TVS) diode in SMC (DO-214AB) package, designed for high-energy surge protection with 1500 W peak pulse power rating, 64 V standoff voltage (VWM), and 103 V maximum clamping voltage (VC) at 14.6 A IPPM. It protects sensitive ICs, MOSFETs, and sensor signal lines in automotive, industrial, and telecom systems against lightning and inductive switching transients.

For engineers reviewing the SMCJ64CAHM3_A/I datasheet, SMCJ64CAHM3_A/I pinout, SMCJ64CAHM3_A/I application, or SMCJ64CAHM3_A/I equivalent, key selection criteria include bidirectional clamping capability, AEC-Q101 qualification, halogen-free RoHS compliance, and compatibility with 10/1000 µs surge waveforms in space-constrained SMC-mount designs.

Technical Context

This device operates as a voltage-clamped shunt protector: under normal conditions it presents high impedance (>1 MΩ leakage at VWM), but triggers into low-impedance conduction when reverse voltage exceeds its breakdown range (71.1–78.6 V at 1 mA). Its glass-passivated junction ensures stable avalanche behavior and fast response (<1 ns).

Designed for surface-mount automation, the SMCJ64CAHM3_A/I meets MSL Level 1 per J-STD-020 (260 °C peak reflow), features matte tin-plated leads compliant with J-STD-002 and JESD 22-B102, and supports bidirectional surge suppression without polarity marking-critical for AC-coupled or differential signal line protection.

Key Specifications

Pinout & Package

Package: SMC (DO-214AB), surface-mount, bidirectional configuration with no polarity marking. Case dimensions: 7.75 mm × 6.22 mm × 2.62 mm (L × W × H); terminals are matte tin-plated leads suitable for automated placement and reflow soldering.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMAJ64CAHE3_A/I and SMCJ64AHE3_A/I, the SMCJ64CAHM3_A/I uniquely combines bidirectional operation, 1500 W surge capacity, AEC-Q101 qualification, and halogen-free construction-making it the preferred choice for high-reliability automotive and industrial designs demanding full-spectrum transient immunity.

Availability

SMCJ64CAHM3_A/I is available at Aetrix Electronics and suitable for automotive ECUs, industrial PLCs, telecom infrastructure, and consumer appliance designs requiring stable component supply with long-term lifecycle support.

Supply support for SMCJ64CAHM3_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 SMCJ series was developed for high-power transient suppression in harsh environments-targeting automotive, industrial, and telecom applications where robustness, consistency, and regulatory compliance are mandatory.

FAQ

What does the "HM3" suffix indicate in SMCJ64CAHM3_A/I?

The HM3 suffix in SMCJ64CAHM3_A/I denotes halogen-free, RoHS-compliant construction meeting IEC 61249-2-21 standards, plus AEC-Q101 qualification for automotive use. It also specifies tape-and-reel packaging in 13-inch reels (I = delivery mode), distinguishing it from commercial-grade M3 or HE3 variants. This makes SMCJ64CAHM3_A/I suitable for safety-critical and environmentally regulated applications.

Is SMCJ64CAHM3_A/I bidirectional, and how does that affect circuit layout?

Yes, SMCJ64CAHM3_A/I is bidirectional-its symmetrical structure provides identical clamping performance for both positive and negative transients, eliminating polarity marking and enabling placement across AC-coupled or floating differential lines without orientation concerns. This simplifies PCB layout versus unidirectional alternatives like SMCJ64AHE3_A/I, which require strict cathode alignment and cannot protect bidirectional signals.

What is the maximum clamping voltage (VC) of SMCJ64CAHM3_A/I, and why does it matter?

The maximum clamping voltage (VC) of SMCJ64CAHM3_A/I is 103 V at 14.6 A peak pulse current (IPPM) under 10/1000 µs waveform conditions. This value defines the highest voltage imposed on protected circuitry during a surge event-directly determining whether downstream components like 75 V-rated MOSFETs or 100 V-capacitors remain within safe operating limits. Lower VC improves system robustness.

Can SMCJ64CAHM3_A/I replace SMCJ64CAHE3_A/I in an existing design?

Yes, SMCJ64CAHM3_A/I is a direct drop-in replacement for SMCJ64CAHE3_A/I in terms of electrical specs, package, and pinout-both are bidirectional 64 V TVS diodes in SMC (DO-214AB) package. The HM3 variant adds halogen-free materials and AEC-Q101 qualification, making it preferable for automotive or green-design applications, with no PCB or schematic changes required.

What thermal derating applies to SMCJ64CAHM3_A/I at elevated ambient temperatures?

SMCJ64CAHM3_A/I must be derated linearly above TA = 25 °C per Figure 2 in the Vishay datasheet (Doc. #88394): power dissipation drops from 6.5 W at 25 °C to zero at +150 °C, with RθJA = 75 °C/W typical. For example, at TA = 85 °C, maximum continuous power reduces to ~4.5 W. Thermal design must use minimum recommended 8.0 mm × 8.0 mm copper pads per terminal to maintain specified surge ratings.