Microchip Technology MAPLAD18KP51AE3

Overview

MAPLAD18KP51AE3 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, features a 51 V reverse standoff voltage (VWM), clamps to ≤82.4 V at 219 A peak impulse current (IPP), and operates across –55 °C to +150 °C. It is qualified to AEC-Q101 and meets RTCA DO-160F Level 5 pin injection and IEC 61000-4-5 Class 2–5 secondary lightning protection requirements.

For engineers reviewing the MAPLAD18KP51AE3 datasheet, MAPLAD18KP51AE3 pinout, MAPLAD18KP51AE3 application, or MAPLAD18KP51AE3 equivalent, key selection criteria include its 51 V VWM rating, 82.4 V max clamping voltage at 219 A, 0.7 °C/W junction-to-case thermal resistance, RoHS-compliant e3 matte-tin plating, and qualification for aircraft-level multi-stroke lightning transients per DO-160 Section 22.

Technical Context

The MAPLAD18KP51AE3 employs an avalanche diode structure optimized for low clamping ratio and minimal thermal resistance. Its metal-base package enables direct heat sinking, supporting sustained surge handling under <0.05% duty cycle conditions per Figure 1 and Figure 2 waveforms. The device exhibits a 60 mV/°C temperature coefficient of breakdown voltage (αV(BR)), ensuring stable clamping performance over temperature.

It is rated for 100% surge testing per lot, with 3σ screening on standby current (ID), and supports secondary lightning protection per IEC 61000-4-5 using 2 Ω, 12 Ω, and 42 Ω source impedances - covering Classes 2–5 depending on impedance configuration. Pin injection immunity per DO-160F Waveform 4 (6.4/69 μs) is validated up to Level 5.

Key Specifications

Pinout & Package

MAPLAD18KP51AE3 uses a surface-mount PLAD package with a metal base acting as the cathode terminal. The package measures 12.32 mm × 10.54 mm × 5.33 mm (L×W×H) and features tin-lead–free annealed matte-tin (e3) plating compliant with RoHS and MIL-STD-750 Method 2026.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMBJ51A and SMCJ51A, MAPLAD18KP51AE3 provides >12× higher peak pulse power, 8× lower thermal resistance, and formal DO-160F Level 5 validation - making it the only option for certified airborne equipment and high-reliability engine bay deployments.

Availability

MAPLAD18KP51AE3 is available at Aetrix Electronics and suitable for aerospace avionics, automotive powertrain systems, and industrial motor drive designs requiring stable component supply, long-term lifecycle support, and traceable high-reliability sourcing.

Supply support for MAPLAD18KP51AE3 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, RF, and timing solutions for aerospace, defense, and industrial markets.

The MAPLAD18KP51AE3 belongs to Microsemi's PLAD family of high-power surface-mount TVS diodes, engineered specifically for multi-stroke lightning protection and load-dump resilience in mission-critical platforms.

FAQ

What is the clamping voltage of MAPLAD18KP51AE3 at its rated peak pulse current?

The MAPLAD18KP51AE3 has a maximum clamping voltage (VC) of 82.4 V at 219 A peak impulse current (IPP) under 10/1000 μs waveform conditions. This value is measured per Figure 3 in the RF01215 datasheet and defines the upper voltage limit imposed on protected circuitry during worst-case surge events. The clamping performance remains stable across –55 °C to +150 °C due to its low αV(BR) of 60 mV/°C.

Is MAPLAD18KP51AE3 qualified for automotive applications?

Yes, MAPLAD18KP51AE3 is fully qualified to AEC-Q101 for automotive use. It undergoes lot-level surge testing, 3σ screening on standby current (ID), and thermal cycling per automotive reliability standards. Its 51 V VWM and 82.4 V clamping voltage make it suitable for 12 V and 24 V battery-fed ECUs, especially where load dump and jump-start transients exceed 100 V.

Does MAPLAD18KP51AE3 meet DO-160F lightning protection requirements?

Yes, MAPLAD18KP51AE3 is validated for RTCA DO-160F Section 22 multi-stroke lightning testing. It achieves Level 5 immunity for pin injection (Waveform 4, 6.4/69 μs) and supports secondary lightning protection per IEC 61000-4-5 across Classes 2–5 with 2 Ω, 12 Ω, and 42 Ω source impedances - confirmed in Rev B of RF01215.

What is the thermal resistance and how does it impact PCB layout for MAPLAD18KP51AE3?

MAPLAD18KP51AE3 has a junction-to-case thermal resistance (RθJC) of 0.7 °C/W. This low value requires direct thermal coupling of its metal base to ≥250 mm² of 2 oz copper on inner or outer layers. Layout must avoid thermal vias under the cathode pad and ensure uninterrupted copper pour beneath the entire footprint to sustain repeated 18 kW surges without junction overheating.

How does the e3 suffix in MAPLAD18KP51AE3 affect assembly and compliance?

The "e3" suffix in MAPLAD18KP51AE3 indicates RoHS-compliant annealed matte-tin plating, compatible with lead-free reflow profiles up to 260 °C for 10 seconds. It eliminates post-assembly cleaning steps, meets IPC/JEDEC J-STD-020B Level 1 moisture sensitivity (no dry pack required), and ensures solderability per MIL-STD-750 Method 2026 - critical for high-yield automated assembly.