Microchip Technology SMAJ36AE3/TR13

Overview

SMAJ36AE3/TR13 from Microsemi is a unidirectional surface-mount transient voltage suppressor (TVS) designed for primary and secondary lightning surge protection in DC power lines and signal interfaces. It features a 36 V working peak standoff voltage (V_WM), 40.0 V minimum breakdown voltage (V_BR), 58.1 V maximum clamping voltage (V_C) at 9.8 A peak pulse current, and 500 W peak pulse power rating per 10/1000 µs waveform - deployed in telecom power supplies, industrial I/O modules, and automotive body control units.

For engineers reviewing the SMAJ36AE3/TR13 datasheet, SMAJ36AE3/TR13 pinout, SMAJ36AE3/TR13 application, or SMAJ36AE3/TR13 equivalent, key selection considerations include its DO-214AC package compatibility, RoHS-compliant matte-tin plating, 100 ps theoretical response time, and IEC61000-4-5 Class 4 secondary lightning compliance with 12 Ω source impedance.

Technical Context

This TVS diode operates as a unidirectional clamping device with cathode-band polarity marking, optimized for fast transient suppression in low-inductance PCB layouts. Its junction-to-lead thermal resistance is 15 °C/W, enabling reliable 5 W steady-state dissipation at 75 °C lead temperature when mounted on FR4 with recommended footprint.

The device meets IEC61000-4-2 (ESD ±8 kV contact), IEC61000-4-4 (EFT ±2 kV), and IEC61000-4-5 (lightning surge: 42 Ω source, Class 4 up to 12 V_WM; 12 Ω source, Class 4 up to 36 V_WM). Standby leakage current is ≤1 μA at 36 V_WM, supporting low-power system monitoring circuits.

Key Specifications

Pinout & Package

Package: DO-214AC (SMA), 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 SMAJ36AHE3/TR13, the SMAJ36AE3/TR13 omits military-grade screening but retains identical clamping behavior and RoHS compliance for cost-sensitive industrial use; versus SMBJ36A-E3/52, it delivers equal protection in a smaller DO-214AC footprint with better thermal coupling to PCB copper.

Availability

SMAJ36AE3/TR13 is available at Aetrix Electronics and suitable for industrial PLC analog inputs, automotive body control module power rails, and telecom DC power feeds requiring stable component supply across multi-year production cycles.

Supply support for SMAJ36AE3/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 developed specifically for surface-mount transient voltage suppression in space-constrained, high-surge environments - emphasizing fast response, repeatable clamping, and robust thermal performance in DO-214AC packaging.

FAQ

What is the clamping voltage of SMAJ36AE3/TR13 at its rated peak pulse current?

The SMAJ36AE3/TR13 has a maximum clamping voltage (V_C) of 58.1 V at 9.8 A peak pulse current (I_PP) under the standard 10/1000 µs waveform. This value is measured per Figure 2 in the Microsemi MSC0270A datasheet and defines the upper voltage limit imposed on protected circuitry during surge events. The SMAJ36AE3/TR13 maintains this clamping performance across its full operating temperature range.

Is SMAJ36AE3/TR13 unidirectional or bidirectional, and how is polarity identified?

SMAJ36AE3/TR13 is a unidirectional TVS diode, indicated by the absence of "C" or "CA" in its part number suffix. Polarity is marked by a cathode band on the banded end of the DO-214AC package; the banded end connects to the protected line (e.g., V_IN), while the unmarked end connects to ground. This configuration ensures clamping only of positive transients relative to ground - critical for DC power rail protection. The SMAJ36AE3/TR13 does not conduct in reverse bias until breakdown occurs.

Does SMAJ36AE3/TR13 comply with IEC61000-4-5 for lightning surge immunity?

Yes, SMAJ36AE3/TR13 complies with IEC61000-4-5 for secondary lightning surge immunity. Specifically, it meets Class 4 requirements when tested with a 12 Ω source impedance (up to 36 V_WM) and Class 1–4 with 42 Ω source impedance (Class 4 applies to ≤12 V_WM). These classifications are confirmed in the Microsemi MSC0270A datasheet, Table on Page 1. The SMAJ36AE3/TR13 achieves this via its 500 W peak pulse power rating and sub-100 ps response time.

What is the maximum steady-state power dissipation of SMAJ36AE3/TR13 on a standard FR4 PCB?

When mounted on a standard FR4 printed circuit board with 1 oz copper and the recommended footprint, SMAJ36AE3/TR13 dissipates up to 1.56 W at ambient temperature (T_A = 25 °C) and 5 W at lead temperature (T_L = 75 °C). This steady-state rating assumes proper thermal relief design and is distinct from its 500 W transient pulse capability. The SMAJ36AE3/TR13's junction-to-lead thermal resistance of 15 °C/W enables this performance, making it suitable for continuous low-power protection tasks.

How does the "e3" and "TR13" suffix in SMAJ36AE3/TR13 affect packaging and compliance?

The "e3" suffix denotes RoHS compliance with annealed matte-tin plating and halogen-free epoxy encapsulation, per IPC/JEDEC J-STD-020B Level 1 moisture sensitivity (no dry pack required). The "TR13" suffix specifies tape-and-reel packaging per EIA-481-1-A: 12 mm carrier tape, 2500 units per 13-inch reel. Both suffixes are integral to the SMAJ36AE3/TR13 ordering code and define its environmental compliance and logistics format - no separate part number variants exist for these attributes.