Microchip Technology MPLAD36KP78CAE3

Overview

MPLAD36KP78CAE3 from Microsemi is a bidirectional surface-mount transient voltage suppressor (TVS) designed for high-energy surge protection in aerospace and automotive systems. It delivers 36 kW peak pulse power at 10/1000 μs, clamps at ≤126 V @ 286 A, and features a 78 V reverse standoff voltage (VWM), RoHS-compliant e3 plating, and thermal resistance of 1.0 °C/W junction-to-case - enabling robust secondary lightning protection per IEC 61000-4-5 and RTCA DO-160F Waveform 5A Level 4.

For engineers reviewing the MPLAD36KP78CAE3 datasheet, MPLAD36KP78CAE3 pinout, MPLAD36KP78CAE3 application, or MPLAD36KP78CAE3 equivalent, key selection criteria include its bidirectional polarity, 78 V VWM rating, 126 V max clamping voltage at 286 A, compliance with RTCA DO-160F Waveform 5A Level 4 (40/120 μs), and suitability for aircraft avionics power rail protection where multi-stroke lightning immunity is required.

Technical Context

This device operates as a silicon avalanche diode-based TVS, leveraging controlled breakdown to shunt transients above its 78 V standoff threshold. Its bidirectional construction enables symmetrical clamping for AC-coupled or floating signal/power lines, and it meets AEC-Q101 stress testing requirements for automotive-grade reliability.

The PLAD package uses a void-free thermosetting epoxy body (UL94V-0) with metal base cathode termination, optimized for low thermal resistance (RθJC = 1.0 °C/W) and high-power dissipation. It supports IEC 61000-4-2 ESD (±30 kV contact), IEC 61000-4-4 EFT (4 kV), and IEC 61000-4-5 surge (42 Ω, 12 Ω, and 2 Ω source impedances) across Class 1–5 severity levels.

Key Specifications

Pinout & Package

Package: PLAD - surface-mount, low-profile thermoset epoxy case with metal base cathode (pin 1). Dimensions: 12.32 × 10.54 × 5.08 mm (L × W × H), weight ~1.85 g. Mounting requires recommended pad layout (A = 11.94 mm, B = 5.85 mm) for optimal thermal performance and mechanical reliability.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMBJ78CA and SMCJ78CA, the MPLAD36KP78CAE3 delivers 24× and 24× higher peak pulse power respectively, enables certified DO-160F and AEC-Q101 deployment, and achieves 10× lower thermal resistance - making it the only option for mission-critical aerospace and high-energy automotive surge protection.

Availability

MPLAD36KP78CAE3 is available at Aetrix Electronics and suitable for aircraft avionics, automotive powertrain systems, industrial motor drives, and railway signaling applications requiring stable component supply, long-term lifecycle support, and traceable high-reliability sourcing.

Supply support for MPLAD36KP78CAE3 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, RF, and timing solutions for aerospace, defense, and industrial markets.

The MPLAD36KP78CAE3 belongs to Microsemi's PLAD-series high-power TVS family, engineered specifically for multi-stroke lightning protection in safety-critical platforms where standard TVS devices fail under cumulative thermal stress.

FAQ

What is the clamping voltage of MPLAD36KP78CAE3 at its rated peak pulse current?

The MPLAD36KP78CAE3 has a maximum clamping voltage (VC) of 126 V at its peak pulse current (IPP) of 286 A under 10/1000 μs waveform conditions. This value is guaranteed per the datasheet's electrical characteristics table and defines the upper voltage limit imposed on protected circuitry during worst-case surge events. The low clamping ratio (VC/VWM ≈ 1.61) ensures effective overvoltage limiting without overstressing downstream components.

Is MPLAD36KP78CAE3 qualified for automotive applications?

Yes, MPLAD36KP78CAE3 is AEC-Q101 qualified, confirming its suitability for automotive powertrain and chassis applications subject to high-energy transients like load dump and inductive switching. Its 78 V VWM rating aligns with 24 V commercial vehicle systems, and its 36 kW PPP rating exceeds ISO 7637-2 Pulse 5a/b requirements. Full qualification test reports are available upon request from Aetrix Electronics.

Does MPLAD36KP78CAE3 meet RTCA DO-160F lightning protection requirements?

Yes, MPLAD36KP78CAE3 is explicitly validated for RTCA DO-160F Section 22 lightning-induced transient protection. It achieves Level 4 immunity for Waveform 5A (40/120 μs) up to 78 V VWM and supports Class 5 secondary lightning protection with 42 Ω source impedance. These capabilities are documented in Microsemi's RF01216 Rev B datasheet and confirmed via third-party test lab reports.

What is the thermal resistance and recommended mounting method for MPLAD36KP78CAE3?

MPLAD36KP78CAE3 has a junction-to-case thermal resistance (RθJC) of 1.0 °C/W, achieved only when the metal base cathode is soldered directly to a minimum 11.94 mm × 5.85 mm copper pad per the specified pad layout. Use of thermal vias and internal copper planes is strongly recommended to manage cumulative heating during multi-pulse events. Failure to follow pad guidelines increases RθJA to 50 °C/W and risks thermal runaway.

How does the bidirectional construction of MPLAD36KP78CAE3 affect its circuit integration?

The bidirectional construction of MPLAD36KP78CAE3 eliminates polarity sensitivity, allowing placement across AC-coupled signal lines, transformer-isolated power rails, or floating bus architectures without orientation concerns. Unlike unidirectional TVS diodes, it provides symmetrical clamping in both directions - essential for protecting differential interfaces or systems where ground reference shifts during transients. Its cathode is the metal base, and anode is the top-side marked terminal.