Microchip Technology SMAJ5.0E3/TR13

Overview

SMAJ5.0E3/TR13 from Microsemi is a unidirectional surface-mount transient voltage suppressor (TVS) designed for primary overvoltage protection of DC power rails and signal lines. It features a 5.0 V working peak standoff voltage (V_WM), 6.4 V minimum breakdown voltage (V_BR) at 10 mA, 9.6 V maximum clamping voltage (V_C) at 52 A peak pulse current, and 500 W peak pulse power rating at 10/1000 µs waveform - deployed in industrial power supplies, automotive ECUs, and USB interface protection.

For engineers reviewing the SMAJ5.0E3/TR13 datasheet, SMAJ5.0E3/TR13 pinout, SMAJ5.0E3/TR13 application, or SMAJ5.0E3/TR13 equivalent, key selection criteria include its 5.0 V V_WM, sub-100 ps response time, DO-214AC (SMA) package compatibility, RoHS-compliant matte-tin plating, and IEC61000-4-2/4-4/4-5 compliance for ESD, EFT, and secondary lightning surge protection.

Technical Context

The SMAJ5.0E3/TR13 operates as a unidirectional avalanche diode with cathode-band polarity marking, optimized for fast clamping of transients on positive-rail circuits. Its junction-to-lead thermal resistance is 15 °C/W, enabling reliable 500 W surge handling when mounted per recommended FR4 footprint with 1 oz copper.

It delivers <100 ps theoretical response from 0 V to V_BR min., supports 40 A forward surge current (8.3 ms half-sine), and maintains ≤800 µA standby leakage at V_WM - meeting Class 4 secondary lightning protection (IEC61000-4-5, 12 Ω source) and full IEC61000-4-2 Level 4 ESD immunity.

Key Specifications

Pinout & Package

Package: DO-214AC (SMA), surface-mount, void-free thermosetting epoxy case with C-bend leads, RoHS-compliant annealed matte-tin plating, moisture sensitivity level 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 SMAJ5.0A, SMAJ5.0E3/TR13 trades tighter leakage control for broader availability and lower cost; versus SMCJ5.0A, it delivers identical clamping performance in 40% smaller area - making it ideal for compact 5 V systems requiring certified IEC61000-4-2/4-4/4-5 protection without layout redesign.

Availability

SMAJ5.0E3/TR13 is available at Aetrix Electronics and suitable for industrial power input protection, automotive body control modules, USB 2.0 data line protection, and POS terminal serial interface applications requiring stable component supply and full RoHS compliance.

Supply support for SMAJ5.0E3/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 developed specifically for surface-mount transient voltage suppression in space-constrained, high-surge environments - delivering 500 W pulse power in the industry-standard DO-214AC package with validated IEC61000-4-x compliance.

FAQ

What is the clamping voltage of SMAJ5.0E3/TR13 at its rated peak pulse current?

The SMAJ5.0E3/TR13 has a maximum clamping voltage (V_C) of 9.6 V at 52 A peak pulse current (I_PP) under the 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 surge events. Maintaining V_C below 10 V ensures compatibility with 5 V logic families and prevents overstress of downstream ICs.

Is SMAJ5.0E3/TR13 unidirectional or bidirectional?

SMAJ5.0E3/TR13 is a unidirectional transient voltage suppressor, indicated by the absence of "C" or "CA" in its part number suffix. It features a cathode band marking and conducts only in reverse bias during overvoltage events. Unlike bidirectional variants (e.g., SMAJ5.0CA), it must be oriented with cathode toward ground and anode toward the protected line - essential for correct operation in DC rail protection.

What package type does SMAJ5.0E3/TR13 use, and what are its key mechanical features?

SMAJ5.0E3/TR13 uses the DO-214AC (SMA) surface-mount package with C-bend leads, void-free UL94V-0 epoxy body, and RoHS-compliant annealed matte-tin plating. Key mechanical features include moisture sensitivity level 1 (no dry pack required), 0.064 g weight, and JEDEC-compliant footprint with 1.70–2.26 mm length (A dimension). Its wide leads provide low thermal resistance (15 °C/W junction-to-lead) for efficient heat dissipation during surge events.

Does SMAJ5.0E3/TR13 meet IEC61000-4-5 for lightning surge protection?

Yes, SMAJ5.0E3/TR13 meets IEC61000-4-5 for secondary lightning surge protection with both 12 Ω and 42 Ω source impedances. Per the Microsemi datasheet, it qualifies for Class 4 (12 Ω source) and Class 1 (42 Ω source) testing, supporting peak pulse currents up to 52 A while maintaining V_C ≤ 9.6 V. This certification applies specifically to the SMAJ5.0–170A series, including SMAJ5.0E3/TR13, and is validated using the 10/1000 µs waveform.

What is the maximum steady-state power dissipation of SMAJ5.0E3/TR13 at room temperature?

The SMAJ5.0E3/TR13 has a maximum steady-state power dissipation of 1.56 W at ambient temperature (T_A) of 25 °C when mounted on an FR4 printed circuit board with 1 oz copper and the recommended pad layout. This rating is derived from its thermal resistance of 80 °C/W junction-to-ambient and is distinct from its 500 W peak pulse rating - steady-state dissipation must remain within this limit to avoid thermal runaway during continuous reverse-bias leakage conditions.