Microchip Technology SMAJ150AE3/TR13

Overview

SMAJ150AE3/TR13 from Microsemi is a unidirectional surface-mount Transient Voltage Suppressor (TVS) in DO-214AC (SMA) package, rated for 500 W peak pulse power at 10/1000 µs, with 150 V standoff voltage (V_WM), 167 V minimum breakdown voltage (V_BR), and 243 A peak pulse current (I_PP). It clamps transients to ≤268 V and is RoHS-compliant (e3 suffix), used for secondary lightning and ESD protection in industrial power supplies and telecom interfaces.

For engineers reviewing the SMAJ150AE3/TR13 datasheet, SMAJ150AE3/TR13 pinout, SMAJ150AE3/TR13 application, or SMAJ150AE3/TR13 equivalent, key selection criteria include clamping voltage margin vs. protected IC's absolute maximum rating, IEC61000-4-5 Class 2 compliance at 12 Ω source impedance, thermal resistance (15 °C/W junction-to-lead), and tape-and-reel packaging (TR13 = 2500/reel).

Technical Context

This TVS operates as a unidirectional avalanche diode, triggered when reverse voltage exceeds V_BR = 167 V (min) at I_BR = 1 mA, entering low-impedance clamping mode within <100 ps. Its 500 W peak pulse rating is defined per 10/1000 µs waveform, with thermal resistance of 15 °C/W junction-to-lead ensuring stable operation under repeated surges at TL = 75 °C.

The device features a void-free thermosetting epoxy case (UL94V-0), C-bend leads with annealed matte-tin plating, and polarity indicated by cathode band. It supports IEC61000-4-2 (ESD), IEC61000-4-4 (EFT), and IEC61000-4-5 (lightning) protection - specifically Class 2 at 12 Ω source impedance (covers up to SMAJ16A/CA, so SMAJ150AE3/TR13 meets Class 1 only at 42 Ω).

Key Specifications

Pinout & Package

Package: DO-214AC (SMA), surface-mount, void-free UL94V-0 epoxy body with C-bend (modified J-bend) leads and cathode band marking. Dimensions: 4.93–5.48 mm (D) × 3.99–4.50 mm (B) × 1.70–2.26 mm (A); weight: 0.064 g.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMAJ150AHE3/TR13, the SMAJ150AE3/TR13 omits avionics screening but retains identical clamping performance and reliability for commercial/industrial use; versus SMBJ150A-E3/52, it trades slightly larger size for superior thermal dissipation (15 vs. 20 °C/W) and proven 500 W surge endurance in harsh environments.

Availability

SMAJ150AE3/TR13 is available at Aetrix Electronics and suitable for industrial power supplies, motor drive DC buses, telecom auxiliary rails, and renewable energy inverters requiring stable component supply with full traceability and long-term lifecycle support.

Supply support for SMAJ150AE3/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, RF, and radiation-hardened components for aerospace, defense, and industrial markets.

The SMAJ series was designed for robust, surface-mount transient suppression in high-energy industrial and telecom infrastructure, emphasizing thermal stability, fast response, and compliance with IEC61000-4-x standards.

FAQ

What is the clamping voltage of SMAJ150AE3/TR13 at its rated peak pulse current?

The SMAJ150AE3/TR13 has a maximum clamping voltage (V_C) of 268 V at its rated peak pulse current (I_PP) of 243 A, measured under the standard 10/1000 µs waveform. This value defines the upper voltage limit imposed on protected circuitry during a full-rated surge event and must be verified against the absolute maximum ratings of downstream ICs to ensure safe operation.

Is SMAJ150AE3/TR13 unidirectional or bidirectional?

SMAJ150AE3/TR13 is a unidirectional TVS diode, indicated by the "A" suffix (as opposed to "CA" or "C" for bidirectional variants). It conducts only in reverse bias above V_BR, with polarity marked by a cathode band. This makes it suitable for DC rail protection where polarity is fixed, unlike bidirectional versions used on AC or differential signal lines.

What does the "e3" and "TR13" suffix mean in SMAJ150AE3/TR13?

The "e3" suffix denotes RoHS-compliant matte-tin plating per JEDEC J-STD-020B Level 1, eliminating dry-pack requirements and supporting lead-free reflow. The "TR13" indicates tape-and-reel packaging: 13-inch reel containing 2500 units, compliant with EIA-481-1-A standards for automated SMT placement.

Can SMAJ150AE3/TR13 be used for IEC61000-4-5 lightning surge protection?

Yes - SMAJ150AE3/TR13 is validated for IEC61000-4-5 secondary lightning protection at Class 1 with 42 Ω source impedance (covers V_WM up to 100 V), and also supports Class 1 at 12 Ω source for lower-voltage variants. While its 150 V rating places it outside Class 2/3/4 at 12 Ω, it remains appropriate for Class 1 applications in 120–200 V DC systems such as industrial power supplies and solar inverters.

What is the thermal resistance and maximum steady-state power dissipation of SMAJ150AE3/TR13?

SMAJ150AE3/TR13 has a junction-to-lead thermal resistance of 15 °C/W and a junction-to-ambient thermal resistance of 80 °C/W when mounted on FR4 with 1 oz Cu and recommended footprint. Its steady-state power dissipation is 5 W at lead temperature (T_L) = 75 °C, or 1.56 W at ambient temperature (T_A) = 25 °C - values critical for thermal design in continuous-duty surge-prone environments.