Microchip Technology SMAJ150CE3/TR13

Overview

SMAJ150CE3/TR13 from Microsemi is a bidirectional surface-mount transient voltage suppressor (TVS) designed for secondary lightning and ESD/EFT protection in power and signal lines. It features a 150 V working standoff voltage (V_WM), 167 V minimum breakdown voltage (V_BR), clamps to ≤268 V at 1 A peak pulse current, delivers 500 W peak pulse power (10/1000 µs), and operates from –65 °C to +150 °C - used in industrial power supplies and telecom interface protection.

For engineers reviewing the SMAJ150CE3/TR13 datasheet, SMAJ150CE3/TR13 pinout, SMAJ150CE3/TR13 application, or SMAJ150CE3/TR13 equivalent, key selection criteria include bidirectional clamping behavior, IEC61000-4-5 Class 1 compliance with 42 Ω source impedance, RoHS-compliant matte-tin plating, DO-214AC package thermal resistance (15 °C/W junction-to-lead), and tape-and-reel packaging (TR13 = 2500/reel).

Technical Context

This bidirectional TVS uses avalanche diode architecture to clamp both positive and negative transients symmetrically around ground. Its <100 ps theoretical response time enables effective suppression of ESD per IEC61000-4-2 and fast switching transients, while its 500 W rating supports robust protection against induced RF and secondary lightning surges.

The device is rated for 1 A breakdown current (I_BR) and exhibits ≤2.1 µA standby leakage at 150 V (V_WM). Its DO-214AC package provides low thermal resistance (15 °C/W junction-to-lead) and is optimized for FR4 PCB mounting with recommended footprint per Microsemi MSC0270A Rev L.

Key Specifications

Pinout & Package

DO-214AC (SMAJ) package: void-free thermosetting epoxy case, C-bend (modified J-bend) leads, matte-tin RoHS-compliant plating, cathode band omitted on bidirectional variants. Weight: 0.064 g. Moisture sensitivity level: 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 SMAJ150CE3/TR13, the Vishay SMAJ150A-E3/5B lacks bidirectional symmetry and demands polarity-aware placement, while the ON Semiconductor 1.5SMC150CA offers higher surge capacity but occupies more board area and incurs higher assembly cost - making SMAJ150CE3/TR13 optimal for space-constrained, cost-sensitive bidirectional protection.

Availability

SMAJ150CE3/TR13 is available at Aetrix Electronics and suitable for industrial power input protection, telecom line interface, automotive body control modules, and medical sensor signal conditioning requiring stable component supply and full traceability.

Supply support for SMAJ150CE3/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 and mixed-signal components for aerospace, defense, and industrial markets.

The SMAJ series was engineered for surface-mount transient suppression in mission-critical systems where consistent clamping performance, extended temperature operation, and MIL-grade screening options are essential.

FAQ

What does the "C" suffix in SMAJ150CE3/TR13 indicate?

The "C" suffix in SMAJ150CE3/TR13 denotes bidirectional construction - meaning the device clamps symmetrically for both positive and negative transients relative to ground. Unlike unidirectional variants (e.g., SMAJ150A), SMAJ150CE3/TR13 has no cathode marking and provides identical V_BR and V_C in either polarity, making it ideal for AC-coupled or floating signal paths where polarity is undefined.

Is SMAJ150CE3/TR13 compliant with IEC61000-4-5 for lightning surge protection?

Yes, SMAJ150CE3/TR13 is validated for IEC61000-4-5 secondary lightning surge immunity with 42 Ω source impedance up to Class 1 (defined for V_WM ≥ 150 V). Its 500 W peak pulse rating and ≤268 V clamping voltage at 1 A ensure protected circuits remain within safe operating limits during standardized 10/1000 µs surge events.

What is the thermal resistance of SMAJ150CE3/TR13, and how does it affect PCB layout?

SMAJ150CE3/TR13 has a junction-to-lead thermal resistance of 15 °C/W. This value assumes mounting on an FR4 board with 1 oz copper and Microsemi's recommended pad layout (MSC0270A Rev L). To maintain reliability under repeated surge stress, designers must provide adequate copper pour area connected to both terminals and avoid narrow traces that increase thermal impedance - otherwise, localized heating may degrade long-term clamping consistency.

Does SMAJ150CE3/TR13 require derating at elevated ambient temperatures?

Yes, SMAJ150CE3/TR13 must be derated above 25 °C ambient per Microsemi's published derating curve (Figure 3 in MSC0270A). At 75 °C ambient, its steady-state power dissipation drops to 5 W; at 125 °C, it falls to ~1.5 W. Peak pulse power remains 500 W only at T_L = 25 °C - sustained surge repetition requires thermal management to prevent cumulative junction temperature rise beyond 150 °C.

How does the "TR13" suffix impact ordering and assembly of SMAJ150CE3/TR13?

The "TR13" suffix indicates tape-and-reel packaging: 2500 units per 13-inch reel, compliant with EIA-481-1-A standards. This format enables direct integration into automated SMT pick-and-place equipment, reduces manual handling errors, and supports JIT manufacturing. Aetrix Electronics ships SMAJ150CE3/TR13 in sealed moisture-barrier bags with desiccant and humidity indicator, preserving its Level 1 MSL rating without dry-pack preconditioning.