Vishay General Semiconductor - Diodes Division SMA5J22CAHM3/I

Overview

SMA5J22CAHM3/I 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 22 V standoff voltage (V_WM), 24.4–26.9 V breakdown range (V_BR), 500 W peak pulse power (10/1000 μs), clamping voltage of 35.5 V at 14.1 A, and operates from –55 °C to +150 °C - used in automotive sensor interfaces and industrial I/O protection.

For engineers reviewing the SMA5J22CAHM3/I datasheet, SMA5J22CAHM3/I pinout, SMA5J22CAHM3/I application, or SMA5J22CAHM3/I equivalent, key selection criteria include bidirectional clamping capability, AEC-Q101 qualification status, halogen-free RoHS compliance, thermal resistance (R_θJA = 80 °C/W), and compatibility with automated SMT placement on 5.0 mm × 5.0 mm copper pads.

Technical Context

This bidirectional TVS diode uses a glass-passivated silicon junction to achieve fast response (<1 ns) and low incremental surge resistance. Its symmetrical clamping behavior ensures equal protection against positive and negative transients without polarity dependence.

Designed for mounting on minimum recommended 0.2" × 0.2" copper pads, it delivers 500 W surge handling per the 10/1000 μs waveform standard (ANSI/IEEE C62.35), with derating above 25 °C per Fig. 2 and meets MSL Level 1 (260 °C peak reflow).

Key Specifications

Pinout & Package

Package: SMA (DO-214AC), surface-mount, halogen-free, RoHS-compliant, with matte tin-plated leads solderable per J-STD-002 and JESD 22-B102. Bidirectional construction means no polarity marking; terminals are symmetric and interchangeable.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMA5J22CAHM3/I, SMA5J22CAHE3/I omits AEC-Q101 validation but matches all electrical and thermal specs, while SMA6J22CAHM3/I increases peak pulse power to 600 W without changing footprint or clamping behavior - enabling direct upgrade in existing layouts where higher surge immunity is needed.

Availability

SMA5J22CAHM3/I is available at Aetrix Electronics and suitable for automotive electronics, industrial programmable logic controllers, telecom infrastructure, and consumer power adapter designs requiring stable component supply with guaranteed AEC-Q101 qualification and halogen-free compliance.

Supply support for SMA5J22CAHM3/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, TVS devices, and optoelectronics with emphasis on reliability, precision, and application-specific performance.

The SMA5J series is engineered for high-power-density transient suppression in space-constrained, high-reliability applications - particularly targeting automotive, industrial, and telecom systems where consistent clamping, thermal stability, and qualification rigor are mandatory.

FAQ

What does the "HM3" suffix indicate in SMA5J22CAHM3/I?

The "HM3" suffix in SMA5J22CAHM3/I denotes halogen-free, RoHS-compliant construction with AEC-Q101 qualification. It confirms compliance with JESD201 Class 2 whisker resistance and maximum peak reflow temperature of 260 °C - critical for automotive and high-reliability industrial use. The "I" indicates 13-inch tape-and-reel packaging (7500 units per reel). SMA5J22CAHM3/I meets these specifications as verified in Vishay document 88875.

Is SMA5J22CAHM3/I suitable for protecting CAN FD bus lines?

Yes, SMA5J22CAHM3/I is suitable for CAN FD bus protection due to its 22 V V_WM, which exceeds typical CAN FD common-mode voltage ranges (±12 V), and its 35.5 V clamping voltage, which stays below the absolute maximum ratings of most CAN FD transceivers (e.g., 40 V). Its bidirectional symmetry preserves differential signal integrity, and AEC-Q101 qualification validates robustness in automotive ECU environments where SMA5J22CAHM3/I is deployed.

How does SMA5J22CAHM3/I compare to unidirectional variants like SMA5J22A HM3/I?

SMA5J22CAHM3/I is bidirectional (denoted by "CA"), providing symmetrical clamping for AC or floating signals, whereas SMA5J22AHM3/I is unidirectional with cathode band marking and forward voltage drop (~3.5 V at 25 A). SMA5J22CAHM3/I has no polarity marking and identical V_WM/V_BR/V_C in both directions - making it appropriate for differential data lines or dual-rail supplies where polarity reversal may occur. Both share the same SMA package and AEC-Q101/halogen-free status.

What is the maximum allowable PCB pad size for optimal thermal performance of SMA5J22CAHM3/I?

For optimal thermal performance, SMA5J22CAHM3/I should be mounted on 0.2" × 0.2" (5.0 mm × 5.0 mm) copper pads per terminal, as specified in Vishay document 88875. This pad size achieves the rated R_θJA of 80 °C/W. Reducing pad area increases thermal resistance and reduces surge current capability; increasing pad size improves heat dissipation but offers diminishing returns beyond 6 mm × 6 mm. SMA5J22CAHM3/I's thermal design must account for this baseline layout to sustain 500 W pulses.

Does SMA5J22CAHM3/I require derating at elevated ambient temperatures?

Yes, SMA5J22CAHM3/I requires derating above 25 °C ambient, per Figure 2 in Vishay document 88875. At 85 °C ambient, its peak pulse power drops to ~70 % of 500 W (≈350 W), and at 125 °C, it falls to ~40 % (≈200 W). This linear derating applies to both P_PPM and I_PPM. Designers must apply this curve when sizing SMA5J22CAHM3/I for under-hood or enclosed industrial environments where sustained high TA is expected.