Microchip Technology MAPLAD18KP28CAE3

Overview

MAPLAD18KP28CAE3 from Microsemi is a bidirectional 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 ≤45.5 V under 396 A peak impulse current, and features a 28 V reverse standoff voltage (VWM) with ±5% breakdown tolerance (31.1–34.4 V). It is qualified to AEC-Q101 and meets RTCA DO-160F Level 4 pin injection for Waveform 4.

For engineers reviewing the MAPLAD18KP28CAE3 datasheet, MAPLAD18KP28CAE3 pinout, MAPLAD18KP28CAE3 application, or MAPLAD18KP28CAE3 equivalent, key selection criteria include its 28 V VWM rating, bidirectional polarity (CA suffix), RoHS-compliant e3 plating, 0.7 °C/W junction-to-case thermal resistance, and compliance with IEC 61000-4-5 (Class 1–4, 2–42 Ω source) and ESD/EFT per IEC 61000-4-2/4-4.

Technical Context

This TVS diode uses an avalanche breakdown mechanism to divert high-energy transients away from sensitive circuitry. Its low RθJC (0.7 °C/W) enables effective heat dissipation when mounted on a heatsink, supporting multi-stroke lightning protection per RTCA DO-160 Section 22. The device operates across –55°C to +150°C junction temperature range and maintains stable clamping performance under repetitive 0.05% duty-cycle impulses.

Designed for secondary lightning protection, MAPLAD18KP28CAE3 supports multiple IEC 61000-4-5 test configurations: Class 1–5 at 42 Ω, Class 1–4 at 12 Ω, and Class 2–4 at 2 Ω source impedance. Its bidirectional construction ensures symmetrical clamping for AC-coupled or floating signal lines, and its <5 ns response time ensures fast suppression of fast-rising transients such as ESD and EFT.

Key Specifications

Pinout & Package

MAPLAD18KP28CAE3 is housed in a surface-mount PLAD package with a metal base acting as the cathode terminal for unidirectional variants; for bidirectional devices like MAPLAD18KP28CAE3, both terminals are symmetrical and non-polarized. The package features void-free UL94V-0 epoxy body, matte-tin (e3) RoHS-compliant plating, and weighs ~1 g.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMBJ28CA and SMCJ28CA, MAPLAD18KP28CAE3 provides 30× and 12× higher peak pulse power respectively, enabling single-device protection against lightning and load dump without derating or paralleling-critical for space-constrained avionics and heavy-duty automotive designs.

Availability

MAPLAD18KP28CAE3 is available at Aetrix Electronics and suitable for avionics power distribution, automotive engine control units, and industrial motor drive I/O requiring stable component supply across extended temperature ranges and high-reliability screening programs.

Supply support for MAPLAD18KP28CAE3 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, mixed-signal, and RF solutions for aerospace, defense, and industrial markets.

The PLAD family-including MAPLAD18KP28CAE3-is engineered for extreme surge environments, targeting aircraft lightning protection, automotive load dump suppression, and railway signaling interface hardening where multi-kilowatt transient absorption is mandatory.

FAQ

What is the clamping voltage of MAPLAD18KP28CAE3 at its rated peak pulse current?

MAPLAD18KP28CAE3 has a maximum clamping voltage (VC) of 45.5 V at 396 A peak pulse current (IPP) under 10/1000 μs waveform conditions. This value is guaranteed across the full operating temperature range and ensures downstream components remain within safe voltage limits during surge events. The clamping performance is verified per Figure 3 in the RF01215 datasheet.

Is MAPLAD18KP28CAE3 suitable for automotive applications requiring AEC-Q101 qualification?

Yes, MAPLAD18KP28CAE3 is explicitly tested and qualified to AEC-Q101 standards, including temperature cycling, humidity bias, and mechanical shock. Its 28 V VWM rating, 18,000 W PPP, and bidirectional construction make it appropriate for 24 V automotive systems such as engine control units and transmission control modules exposed to load dump and ISO 7637-2 pulses.

Does MAPLAD18KP28CAE3 meet RTCA DO-160F lightning protection requirements?

Yes, MAPLAD18KP28CAE3 is certified for RTCA DO-160F Section 22 multi-stroke lightning testing and supports Waveform 4 (6.4/69 μs) Level 4 pin injection protection. Its low clamping voltage and high PPP enable compliance in avionics power inputs and sensor interfaces where strict voltage limiting is mandated for flight-critical subsystems.

What is the thermal resistance specification for MAPLAD18KP28CAE3, and how does it impact layout?

MAPLAD18KP28CAE3 has a junction-to-case thermal resistance (RθJC) of 0.7 °C/W. This low value requires direct thermal coupling to a heatsink or copper pour via its metal base. Layout must follow the recommended pad dimensions (12.32–12.57 mm × 10.54–10.80 mm) to maintain thermal performance and avoid derating of PPP under repetitive surge conditions.

How does the CA suffix in MAPLAD18KP28CAE3 affect its electrical behavior?

The CA suffix in MAPLAD18KP28CAE3 denotes bidirectional construction, meaning the device provides symmetrical clamping for both positive and negative transients. Unlike unidirectional variants (e.g., MAPLAD18KP28AE3), MAPLAD18KP28CAE3 has no polarity marking and can be used on AC-coupled lines, differential buses, or floating grounds without orientation constraints.