Vishay General Semiconductor - Diodes Division SMA5J24CA-M3/5A

Overview

SMA5J24CA-M3/5A from Vishay General Semiconductor is a bidirectional transient voltage suppressor (TVS) diode in SMA (DO-214AC) package, designed for high-energy surge protection on signal and power lines. It features a 24 V stand-off voltage (VWM), 38.9 V clamping voltage (VC) at 12.9 A peak pulse current (IPPM), and 500 W peak pulse power (PPPM) with 10/1000 µs waveform - deployed in automotive sensor interfaces and industrial I/O protection.

For engineers reviewing the SMA5J24CA-M3/5A datasheet, SMA5J24CA-M3/5A pinout, SMA5J24CA-M3/5A application, or SMA5J24CA-M3/5A equivalent, key selection criteria include bidirectional clamping capability, halogen-free RoHS compliance (M3 suffix), AEC-Q101 qualification readiness, thermal resistance (RθJA = 80 °C/W), and compatibility with automated SMT placement on 5.0 mm × 5.0 mm copper pads.

Technical Context

This device operates as a voltage-clamped crowbar during transients, leveraging an avalanche breakdown mechanism with glass-passivated junction for stable VBR (26.7–29.5 V) and low incremental surge resistance. Its bidirectional symmetry ensures identical clamping in both polarities, eliminating polarity-sensitive layout constraints.

Designed for fast response (<1 ns), it handles non-repetitive 10/1000 µs surges up to 500 W while maintaining TJ ≤ 150 °C under derated conditions. The SMA package supports MSL Level 1 moisture sensitivity and 260 °C lead-free reflow per J-STD-020.

Key Specifications

Pinout & Package

Package: SMA (DO-214AC), surface-mount, bidirectional - no polarity marking; symmetrical two-terminal construction.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMA5J24CA-M3/5A, the E3 variant offers lower unit cost for non-automotive use, while the HM3_A/I variant adds AEC-Q101 validation and larger reel packaging - neither is pin-compatible in the sense of drop-in replacement due to differing qualification status and reel logistics, but all share identical electrical and mechanical form factor.

Availability

SMA5J24CA-M3/5A is available at Aetrix Electronics and suitable for automotive sensor interfaces, industrial PLC I/O protection, and telecom line interface applications requiring stable component supply, halogen-free compliance, and SMT-ready packaging.

Supply support for SMA5J24CA-M3/5A 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, power density, and automotive-grade qualification.

The SMA5J series is engineered for high-power-density transient suppression in space-constrained, high-reliability systems - targeting automotive, industrial, and telecom applications where robustness against ISO 7637-2 and IEC 61000-4-5 threats is mandatory.

FAQ

What is the clamping voltage of SMA5J24CA-M3/5A at its rated peak pulse current?

The SMA5J24CA-M3/5A has a maximum clamping voltage (VC) of 38.9 V at 12.9 A peak pulse current (IPPM) under 10/1000 µs waveform conditions. This value defines the upper voltage limit imposed on protected circuitry during surge events and is measured per ANSI/IEEE C62.35 standards. The SMA5J24CA-M3/5A maintains this clamping performance bidirectionally, making it suitable for AC-coupled or floating signal paths where polarity cannot be assumed.

Is SMA5J24CA-M3/5A suitable for automotive applications?

SMA5J24CA-M3/5A itself is not AEC-Q101 qualified, but it shares identical electrical and mechanical specifications with the AEC-Q101-qualified variant SMA5J24CAHM3_A/I. The M3 suffix confirms halogen-free, RoHS-compliant construction and MSL Level 1 rating - essential for automotive assembly processes. For production automotive use, the HM3_A/I version must be specified; SMA5J24CA-M3/5A is appropriate for prototyping, industrial, or consumer designs where full qualification is not mandated.

What does the "CA" suffix indicate in SMA5J24CA-M3/5A?

The "CA" suffix in SMA5J24CA-M3/5A denotes a bidirectional configuration - meaning the device provides symmetrical transient voltage suppression in both forward and reverse directions. Unlike unidirectional "A" versions (e.g., SMA5J24A), the CA variant has no cathode band marking and functions identically regardless of voltage polarity applied across its terminals. This eliminates orientation errors during automated placement and simplifies design for AC signals or differential buses like RS-485.

What is the thermal resistance of SMA5J24CA-M3/5A, and how does it affect layout?

The SMA5J24CA-M3/5A has a typical junction-to-ambient thermal resistance (RθJA) of 80 °C/W when mounted on 0.2" × 0.2" (5.0 mm × 5.0 mm) copper pads per terminal. This value assumes standard FR-4 PCB with no internal copper planes. To maintain TJ ≤ 150 °C under repetitive surge conditions, designers must ensure adequate copper area and avoid excessive trace length. The SMA5J24CA-M3/5A's RθJA directly informs minimum pad size and thermal via placement in high-duty-cycle applications.

How does the M3 suffix differ from E3 in SMA5J24CA-M3/5A?

The M3 suffix in SMA5J24CA-M3/5A indicates halogen-free, RoHS-compliant construction, whereas E3 denotes RoHS-compliant but not halogen-free material. Both meet JEDEC JESD201 Class 2 whisker resistance and J-STD-002 solderability standards. The M3 variant is required for compliance with stricter environmental regulations such as China RoHS II and certain automotive OEM specifications. Electrically and dimensionally, SMA5J24CA-M3/5A and SMA5J24CA-E3/5A are identical - only the molding compound composition differs.