Microchip Technology MAPLAD18KP120AE3

Overview

MAPLAD18KP120AE3 from Microsemi is a unidirectional surface-mount transient voltage suppressor (TVS) designed for high-energy surge protection in aerospace and automotive systems. It delivers 18,000 W peak pulse power at 10/1000 μs, clamps at ≤193 V under 100 A peak impulse current, and features a 120 V reverse standoff voltage (VWM) with ±5% breakdown tolerance (133–147 V). Its metal-base thermal design enables low junction-to-case resistance (0.7 °C/W), supporting lightning protection per RTCA DO-160 Section 22 and IEC 61000-4-5 Class 4.

For engineers reviewing the MAPLAD18KP120AE3 datasheet, MAPLAD18KP120AE3 pinout, MAPLAD18KP120AE3 application, or MAPLAD18KP120AE3 equivalent, key selection criteria include its 120 V VWM rating, 193 V max clamping voltage at 100 A, RoHS-compliant e3 plating, 1 g mass, and compatibility with FR4 PCB mounting using specified pad layout per RF01215 Rev B.

Technical Context

This TVS diode operates as a unidirectional clamping device where the cathode is the metal base (bottom side), requiring correct PCB orientation for polarity-sensitive circuits. Its silicon avalanche structure provides fast response (<100 ps) to transients and supports multi-stroke lightning compliance via thermal management enabled by void-free epoxy packaging and direct metal thermal path.

It meets AEC-Q101 stress testing requirements and supports secondary lightning protection per IEC 61000-4-5 with 42 Ω, 12 Ω, and 2 Ω source impedances - specifically Class 1–4 at 42 Ω and Class 2–3 at 2 Ω - validated for MAPLAD18KP120A/CA variants per datasheet Table on page 4.

Key Specifications

Pinout & Package

The PLAD package is a surface-mount, metal-base device with two terminals: anode and cathode. The cathode is the exposed metal base (bottom side), while the anode connects to the top-side metallized pad. Polarity must be observed during placement to ensure proper clamping direction.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMBJ120A and SMCJ120A, MAPLAD18KP120AE3 delivers 30× higher peak pulse power, a metal-base thermal interface enabling >71 W steady-state dissipation, and formal qualification for RTCA DO-160F Level 4/5 - making it the only viable option for certified aerospace and high-reliability automotive applications.

Availability

MAPLAD18KP120AE3 is available at Aetrix Electronics and suitable for aerospace avionics, automotive ECU power protection, and industrial motor drive DC bus applications requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for MAPLAD18KP120AE3 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 Corporation (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 PLAD-series TVS diodes were developed to meet stringent RTCA DO-160 and AEC-Q101 requirements for airborne and automotive power electronics, emphasizing thermal robustness, multi-stroke surge endurance, and lot-traceable manufacturing.

FAQ

What is the clamping voltage of MAPLAD18KP120AE3 at its rated peak pulse current?

The MAPLAD18KP120AE3 has a maximum clamping voltage (VC) of 193 V when subjected to a 100 A peak impulse current (IPP) under the standard 10/1000 μs waveform. This value is measured per Figure 3 and Table on page 4 of RF01215 Rev B and defines the upper voltage limit imposed on protected circuitry during surge events. The actual clamping voltage of MAPLAD18KP120AE3 may be lower depending on current magnitude and waveform shape.

Is MAPLAD18KP120AE3 qualified for automotive applications per AEC-Q101?

Yes, MAPLAD18KP120AE3 is tested in accordance with AEC-Q101 requirements as stated on page 2 of RF01215 Rev B. This qualification confirms its suitability for automotive power electronics including engine control units and battery management systems. The MAPLAD18KP120AE3 undergoes stress testing for temperature cycling, humidity bias, and surge robustness to ensure reliability in harsh vehicular environments.

How does the metal base of MAPLAD18KP120AE3 improve thermal performance?

The metal base of MAPLAD18KP120AE3 serves as the cathode and provides a direct thermal conduction path from the silicon junction to the PCB copper pour or heatsink, achieving a junction-to-case thermal resistance (RθJC) of just 0.7 °C/W. This allows MAPLAD18KP120AE3 to dissipate up to 71 W at TC = 100°C (per Figure 3 derating curve), far exceeding plastic-body alternatives and enabling reliable operation under repeated surge conditions.

Does MAPLAD18KP120AE3 meet RTCA DO-160 lightning protection standards?

Yes, MAPLAD18KP120AE3 is explicitly listed for pin injection protection per RTCA/DO-160F Waveform 4 (Level 4) and Waveform 5A (Level 4 up to 36 V variants) on page 1 of RF01215 Rev B. While MAPLAD18KP120AE3 falls outside the 7.0–130 V range cited for Level 5 Waveform 4, its 120 V rating qualifies it for Level 4 compliance and multi-stroke lightning mitigation in aircraft power distribution systems.

What is the meaning of the "E3" suffix in MAPLAD18KP120AE3?

Per RF01215 Rev B page 2, the "E3" suffix in MAPLAD18KP120AE3 indicates RoHS-compliant annealed matte-tin plating on the terminals, fully compatible with lead-free reflow soldering processes up to 260°C for 10 seconds. This distinguishes MAPLAD18KP120AE3 from non-RoHS versions (blank suffix) and ensures compliance with environmental regulations without compromising solderability or intermetallic formation control.