Microchip Technology MPLAD36KP85A

Overview

MPLAD36KP85A from Microsemi is a unidirectional surface-mount transient voltage suppressor (TVS) designed for high-energy surge protection in aerospace and automotive power systems. It delivers 36 kW peak pulse power at 10/1000 μs, clamps at ≤137 V under 263 A peak impulse current, and features a 78 V reverse standoff voltage (V_WM) with 86.7–95.8 V breakdown range (V_BR). It is qualified to AEC-Q101 and meets RTCA DO-160 Section 22 multi-stroke lightning requirements.

For engineers reviewing the MPLAD36KP85A datasheet, MPLAD36KP85A pinout, MPLAD36KP85A application, or MPLAD36KP85A equivalent, key selection criteria include its 78 V working voltage rating, low 1.0 °C/W junction-to-case thermal resistance, RoHS-compliant e3 plating, and suitability for secondary lightning protection per IEC 61000-4-5 with 42 Ω source impedance up to Class 5 (short distance).

Technical Context

The MPLAD36KP85A operates as a silicon avalanche diode-based unidirectional TVS, leveraging controlled avalanche breakdown to clamp transients. Its metal-base cathode construction enables direct thermal coupling to PCB copper or heatsinks, supporting high-reliability operation under repetitive surges at ≤0.05% duty factor.

It is characterized for clamping performance at 25°C with defined derating above 25°C ambient, and complies with IEC 61000-4-2 (ESD), IEC 61000-4-4 (EFT), and RTCA/DO-160F Waveform 4 & 5A pin-injection standards. Standby leakage (I_D) is 3σ lot-norm screened at ≤10 μA @ 78 V.

Key Specifications

Pinout & Package

Package: PLAD (Plastic Leaded Anode Down) - void-free UL94V-0 epoxy body with metal base cathode terminal; dimensions: 12.32 × 10.54 × 5.08 mm (L × W × H); weight: ~1.85 g; RoHS-compliant matte-tin plating (e3).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMBJ78A and SMCJ78A, the MPLAD36KP85A provides 24× and 24× higher peak power handling respectively, integrated thermal management via metal base, and formal qualification for aerospace and automotive safety-critical systems-making it irreplaceable where multi-stroke survivability and supply-chain traceability are mandatory.

Availability

MPLAD36KP85A is available at Aetrix Electronics and suitable for avionics power distribution, automotive load dump protection, and industrial motor drive DC bus applications requiring stable component supply across extended product lifecycles.

Supply support for MPLAD36KP85A 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) designs high-reliability semiconductor solutions for aerospace, defense, and industrial markets, with emphasis on radiation-hardened ICs, timing devices, and power protection components.

The MPLAD36KP85A belongs to Microsemi's high-power PLAD-series TVS family, engineered specifically for multi-stroke lightning and load-dump protection in mission-critical platforms where thermal robustness and qualification compliance are non-negotiable.

FAQ

What is the clamping voltage of MPLAD36KP85A at its rated peak pulse current?

The MPLAD36KP85A has a maximum clamping voltage (V_C) of 137 V at 263 A peak pulse current (I_PP) under 10/1000 μs waveform conditions. This value is measured per Figure 3 in the RF01216 datasheet and defines the upper voltage limit imposed on protected circuits during worst-case surge events. The MPLAD36KP85A maintains this clamping performance across its qualified temperature range when mounted per recommended pad layout.

Is MPLAD36KP85A RoHS compliant and what does the 'e3' marking indicate?

Yes, MPLAD36KP85A is RoHS compliant, indicated by the 'e3' suffix in its full part number (MPLAD36KP85A-e3). This denotes annealed matte-tin plating per J-STD-020B Level 1 moisture sensitivity, eliminating dry-pack requirements. The MPLAD36KP85A meets EU Directive 2011/65/EU and is compatible with standard lead-free reflow profiles up to 260°C for 10 seconds.

Does MPLAD36KP85A support bidirectional transient suppression?

No, MPLAD36KP85A is unidirectional only. Bidirectional variants carry the 'CA' suffix (e.g., MPLAD36KP85CA). The MPLAD36KP85A features cathode polarity on the metal base and anode on the top surface pad, making it suitable for DC-biased lines like 28 V aircraft buses or automotive battery feeds where reverse voltage is not expected.

What thermal management considerations apply to MPLAD36KP85A in high-duty-cycle applications?

MPLAD36KP85A requires direct thermal coupling of its metal base to a heatsink or ≥2 oz copper ground plane to maintain junction temperature below 150°C. Its 1.0 °C/W R_θJC assumes optimal mounting; derating is necessary above 25°C ambient per Figure 5. For repetitive surges, duty factor must remain ≤0.05% to avoid cumulative heating-verified in the RF01216 datasheet. The MPLAD36KP85A's thermal path is integral to its 36 kW rating.

Which industry standards does MPLAD36KP85A meet for lightning protection?

MPLAD36KP85A meets RTCA DO-160F Section 22 Level 4 and Level 5 for multi-stroke lightning (Waveform 4 and 5A), and IEC 61000-4-5 Class 4 and Class 5 (42 Ω source) for secondary lightning protection. These certifications are explicitly listed in the RF01216 datasheet for MPLAD36KP85A, confirming its suitability for aircraft power systems and rail signaling infrastructure where standardized surge immunity is mandated.