Microchip Technology MAPLAD18KP24CA

Overview

MAPLAD18KP24CA 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 transients to ≤38.9 V at 463 A, and features a 24 V reverse standoff voltage (VWM) with ±5% breakdown tolerance (26.7–29.5 V). It is qualified to AEC-Q101 and meets RTCA DO-160F Waveform 4 Level 4 and IEC 61000-4-5 Class 1–5 secondary lightning protection requirements.

For engineers reviewing the MAPLAD18KP24CA datasheet, MAPLAD18KP24CA pinout, MAPLAD18KP24CA application, or MAPLAD18KP24CA equivalent, this device is selected for high-reliability DC bus protection where multi-stroke lightning immunity, low thermal resistance (RθJC = 0.7 °C/W), and RoHS-compliant SMT mounting are critical - especially in avionics power distribution, engine control units, and rail traction inverters.

Technical Context

The MAPLAD18KP24CA employs an avalanche diode structure optimized for fast response (<5 ns clamping time) and repeatable multi-pulse energy handling. Its metal-base package enables direct thermal coupling to heatsinks, supporting sustained operation under 0.05% duty-cycle impulses per Figure 1 and derated PPP above 100°C per Figure 3.

It operates bidirectionally with symmetrical clamping behavior, meeting IEC 61000-4-2 ESD (±30 kV contact), IEC 61000-4-4 EFT (40 A), and IEC 61000-4-5 surge (42 Ω, 2 Ω, and 12 Ω source impedances) across defined classes. Polarity marking follows cathode-on-base convention per PLAD mechanical layout.

Key Specifications

Pinout & Package

MAPLAD18KP24CA uses a low-profile, void-free thermosetting epoxy surface-mount package (PLAD) with metal base acting as cathode terminal. Dimensions: 12.32 × 10.54 × 5.08 mm (L × W × H), weight ≈1 g. Mounting requires recommended pad layout per RF01215 Rev B, page 7.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMBJ24CA and SMCJ24CA, MAPLAD18KP24CA provides 12× and 12× higher peak pulse power respectively, certified thermal performance for conduction-cooled layouts, and formal qualification for aviation and automotive safety-critical systems - making it the sole option for designs requiring DO-160F Level 4 or AEC-Q101 validation.

Availability

MAPLAD18KP24CA is available at Aetrix Electronics and suitable for avionics power distribution, automotive engine control units, and industrial motor drive DC link protection requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for MAPLAD18KP24CA 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 power solutions for aerospace, defense, and industrial markets.

The MAPLAD18KP24CA belongs to Microsemi's high-power PLAD family, engineered specifically for multi-stroke lightning protection and load-dump immunity in mission-critical platforms where thermal robustness and regulatory compliance are non-negotiable.

FAQ

What is the clamping voltage of MAPLAD18KP24CA at its rated peak pulse current?

The MAPLAD18KP24CA has a maximum clamping voltage (VC) of 38.9 V at its peak pulse current (IPP) of 463 A under 10/1000 μs waveform conditions. This value is measured per Figure 3 in RF01215 Rev B and defines the upper voltage limit imposed on protected circuits during worst-case surge events. The MAPLAD18KP24CA maintains this clamping performance across its qualified temperature range of –55°C to +150°C.

Does MAPLAD18KP24CA require heatsinking for full 18 kW pulse capability?

Yes - the MAPLAD18KP24CA achieves its full 18,000 W peak pulse power rating only when mounted on a PCB with the recommended pad layout (per RF01215 Rev B, page 7) and thermally coupled to a heatsink or large copper plane. Its junction-to-case thermal resistance is 0.7 °C/W, meaning effective heat extraction is mandatory to prevent thermal runaway during repeated surges. Without adequate heatsinking, PPP must be derated per Figure 3.

Is MAPLAD18KP24CA compliant with RoHS and halogen-free standards?

Yes - MAPLAD18KP24CA carries the "e3" suffix, indicating RoHS-compliant matte-tin plating per J-STD-020B Level 1 moisture sensitivity, with no dry pack required. While the datasheet confirms RoHS compliance, it does not specify halogen-free status; therefore, halogen-free compliance cannot be asserted for MAPLAD18KP24CA without additional Microsemi documentation.

Can MAPLAD18KP24CA replace unidirectional TVS diodes in existing designs?

MAPLAD18KP24CA is bidirectional and may replace unidirectional devices only if the circuit topology supports symmetrical clamping - such as AC signal lines or floating DC buses. It cannot substitute for unidirectional TVS diodes in grounded-positive or grounded-negative configurations without verifying that reverse conduction paths are acceptable. Always validate voltage polarity, grounding scheme, and clamping symmetry before substitution.

What testing standards does MAPLAD18KP24CA meet for automotive applications?

MAPLAD18KP24CA is qualified to AEC-Q101 for stress testing including temperature cycling, humidity, and mechanical shock. It also meets IEC 61000-4-5 (lightning surge), IEC 61000-4-2 (ESD), and IEC 61000-4-4 (EFT) - all critical for automotive ECU protection. However, it is not explicitly validated for ISO 7637-2 load dump waveforms; system-level testing is required to confirm suitability for 12 V battery line protection.