Microchip Technology SMAJ6.5CAE3/TR13

Overview

SMAJ6.5CAE3/TR13 from Microsemi is a bidirectional surface-mount transient voltage suppressor (TVS) designed for robust ESD, EFT, and secondary lightning surge protection in DC power rails and signal lines. It features a 6.5 V reverse standoff voltage (V_WM), 7.22 V minimum breakdown voltage (V_BR), clamps transients to ≤12.3 V at 40.7 A peak pulse current (I_PP), and delivers 500 W peak pulse power (10/1000 µs). It is widely deployed in industrial I/O modules and telecom interface circuits.

For engineers reviewing the SMAJ6.5CAE3/TR13 datasheet, SMAJ6.5CAE3/TR13 pinout, SMAJ6.5CAE3/TR13 application, or SMAJ6.5CAE3/TR13 equivalent, key selection criteria include bidirectional clamping capability, IEC61000-4-2/4-4/4-5 compliance, DO-214AC package thermal performance, and RoHS-compliant matte-tin plating - all verified for this exact part number.

Technical Context

This bidirectional TVS operates symmetrically across both polarities, enabling protection of AC-coupled or floating signal paths without polarity constraints. Its <100 ps theoretical response time (unidirectional) and <5 ns for bidirectional operation ensures sub-nanosecond suppression of fast transients like ESD contact discharge.

The device uses silicon avalanche diode technology housed in a void-free thermosetting epoxy case (UL94V-0), with C-bend leads optimized for solderability and thermal conduction. Junction-to-lead thermal resistance is 15 °C/W, supporting reliable 500 W surge handling when mounted on FR4 with recommended footprint.

Key Specifications

Pinout & Package

Package: DO-214AC (SMA), surface-mount, bidirectional configuration with no polarity marking. Void-free UL94V-0 epoxy body, matte-tin plated C-bend leads, 0.064 g weight, moisture sensitivity level (MSL) 1 - no dry pack required.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMAJ6.5CAE3/TR13, Littelfuse's SMAJ6.5CA offers identical surge performance without RoHS compliance, while Vishay's SMAJ6.5CAHM3 adds AEC-Q200 qualification and production screening - making it suitable for automotive deployments where the base Microsemi part meets industrial but not automotive reliability requirements.

Availability

SMAJ6.5CAE3/TR13 is available at Aetrix Electronics and suitable for industrial I/O protection, telecom line interface, and automotive body control module designs requiring stable component supply, RoHS compliance, and IEC61000-4-2/4-4/4-5 certified surge immunity.

Supply support for SMAJ6.5CAE3/TR13 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

Microsemi (now part of Microchip Technology) is a U.S.-based semiconductor company specializing in high-reliability analog, mixed-signal, and radiation-hardened components for aerospace, defense, and industrial markets.

The SMAJ series was engineered for surface-mount transient suppression in harsh environments, emphasizing robust surge handling, wide temperature operation, and compatibility with automated assembly - targeting industrial control, telecom infrastructure, and transportation systems.

FAQ

What is the clamping voltage of SMAJ6.5CAE3/TR13 at its rated peak pulse current?

The SMAJ6.5CAE3/TR13 clamps to a maximum of 12.3 V at its rated peak pulse current of 40.7 A (10/1000 µs waveform). This value is measured per Figure 2 in the official Microsemi datasheet MSC0270A and defines the upper voltage limit imposed on protected circuitry during a full-rated surge event. The clamping voltage remains stable across its operating temperature range of –65 °C to +150 °C.

Is SMAJ6.5CAE3/TR13 RoHS compliant and what does the "e3" suffix indicate?

Yes, SMAJ6.5CAE3/TR13 is RoHS compliant. The "e3" suffix explicitly denotes annealed matte-tin plating per J-STD-020B MSL Level 1, satisfying EU RoHS Directive 2011/65/EU and China RoHS II requirements. This plating ensures solderability without lead content and eliminates the need for dry packing - confirmed in the Microsemi datasheet revision L, page 1.

How does SMAJ6.5CAE3/TR13 differ from unidirectional variants like SMAJ6.5A?

SMAJ6.5CAE3/TR13 is bidirectional, meaning it clamps transients of either polarity symmetrically - ideal for AC lines or floating signals. In contrast, SMAJ6.5A is unidirectional with a cathode band and only clamps in reverse bias. The "CA" suffix confirms bidirectional construction, and its V_BR (7.22 V) and V_C (12.3 V) apply equally to both directions, unlike SMAJ6.5A's forward surge rating (40 A, 3.5 V) which does not exist in the CA version.

What IEC standards does SMAJ6.5CAE3/TR13 meet for surge immunity?

SMAJ6.5CAE3/TR13 is verified for IEC61000-4-2 (ESD ±8 kV contact), IEC61000-4-4 (EFT ±4 kV), and IEC61000-4-5 (lightning surge) with 42 Ω source impedance up to Class 4 (1 kV) and 12 Ω source impedance up to Class 2 (1 kV), as documented in the Microsemi datasheet MSC0270A, page 1. These ratings are intrinsic to the SMAJ6.5CA family and apply directly to SMAJ6.5CAE3/TR13.

What is the thermal resistance and power derating behavior of SMAJ6.5CAE3/TR13?

SMAJ6.5CAE3/TR13 has a junction-to-lead thermal resistance of 15 °C/W and junction-to-ambient of 80 °C/W when mounted on FR4 with 1 oz copper and the recommended footprint. Its steady-state power dissipation is 5 W at 75 °C lead temperature, derating linearly to zero at 150 °C - per Figure 3 in the Microsemi datasheet. This enables reliable operation in high-temperature industrial enclosures without forced cooling.