Microchip Technology MXPLAD36KP48A

Overview

MXPLAD36KP48A from Microsemi is a surface-mount unidirectional 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 ≤77.4 V under 466 A peak impulse current, and features 48 V reverse standoff voltage with 53.3–58.9 V breakdown range. It is qualified to AEC-Q101 and meets RTCA DO-160 Section 22 multi-stroke lightning requirements.

For engineers reviewing the MXPLAD36KP48A datasheet, MXPLAD36KP48A pinout, MXPLAD36KP48A application, or MXPLAD36KP48A equivalent, this device is selected for high-reliability DC bus protection where low thermal resistance, IEC 61000-4-5 Class 4 compliance (42 Ω source), and DO-160F Waveform 4 Level 4 immunity are mandatory design criteria.

Technical Context

The MXPLAD36KP48A operates as a silicon avalanche diode configured for unidirectional clamping on positive-going transients. Its metal-base cathode construction enables direct thermal coupling to PCB copper or heatsinks, achieving 1.0 °C/W junction-to-case thermal resistance. It responds within <100 ps to reach breakdown and clamp at rated IPP.

It is characterized per IEC 61000-4-5 with 42 Ω, 12 Ω, and 2 Ω source impedances, supporting Class 1–5 secondary lightning protection depending on distance and impedance. Pin injection testing per DO-160F Waveform 4 (6.4/69 μs) confirms Level 4 immunity up to 48 V standoff.

Key Specifications

Pinout & Package

MXPLAD36KP48A uses a void-free transfer-molded thermosetting epoxy package (UL94V-0) with tin-lead or RoHS-compliant matte-tin plating. The metal base serves as the cathode terminal and provides primary thermal path. Dimensions: 12.32 × 10.54 × 5.08 mm (L × W × H).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMBJ48A and SMCJ48A, the MXPLAD36KP48A provides 36 kW surge capacity, sub-100 ps response, and certified DO-160F/IEC 61000-4-5 compliance - making it the only option for mission-critical aerospace and heavy-duty industrial DC bus protection.

Availability

MXPLAD36KP48A is available at Aetrix Electronics and suitable for aerospace avionics, automotive load dump protection, and industrial motor drive DC link applications requiring stable component supply, long-term lifecycle support, and traceable high-reliability sourcing.

Supply support for MXPLAD36KP48A 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 analog, mixed-signal, and power semiconductors for aerospace, defense, and industrial markets.

The MPLAD family is engineered for ultra-high-energy transient suppression in safety-critical systems, with emphasis on thermal robustness, DO-160 compliance, and AEC-Q101 qualification.

FAQ

What is the clamping voltage specification for MXPLAD36KP48A under maximum rated surge current?

The MXPLAD36KP48A has a maximum clamping voltage (VC) of 77.4 V when subjected to its peak pulse current (IPP) of 466 A under the standard 10/1000 μs waveform. This value is measured at 25°C and represents the upper limit of voltage imposed on the protected circuit during worst-case surge conditions. The MXPLAD36KP48A maintains this clamping performance while sustaining 36,000 W peak pulse power, distinguishing it from lower-power TVS devices.

Is MXPLAD36KP48A compliant with RTCA DO-160F for aircraft lightning protection?

Yes, MXPLAD36KP48A is validated for RTCA DO-160F Section 22 multi-stroke lightning testing. Specifically, it meets Waveform 4 (6.4/69 μs) Level 4 immunity and Waveform 5A (40/120 μs) Level 4 up to 78 V standoff. Its 36 kW rating and low thermal resistance enable reliable performance across repeated lightning-induced transients - a key requirement for flight-critical power buses where the MXPLAD36KP48A is deployed.

How does the thermal design of MXPLAD36KP48A differ from standard SMT TVS diodes?

The MXPLAD36KP48A uses a metal-base package where the cathode forms the entire bottom surface, enabling direct thermal conduction to PCB copper or external heatsinks. With a junction-to-case thermal resistance (RθJC) of just 1.0 °C/W - versus >10 °C/W for typical SMB/SMA packages - the MXPLAD36KP48A dissipates surge energy more efficiently. This allows the MXPLAD36KP48A to handle repetitive surges without thermal runaway, a critical advantage in avionics and industrial systems.

Does MXPLAD36KP48A support bidirectional transient suppression?

No, MXPLAD36KP48A is a unidirectional TVS diode. Its polarity is fixed: the metal base is the cathode, and the top surface pad is the anode. Bidirectional variants in the same family carry a "CA" suffix (e.g., MXPLAD36KP48CA). Using MXPLAD36KP48A for AC or bipolar surge protection would result in forward conduction during negative transients, potentially damaging the device or failing to protect the circuit.

What is the recommended PCB pad layout for optimal thermal and electrical performance of MXPLAD36KP48A?

The manufacturer specifies a minimum pad layout of 11.94 mm × 5.85 mm (A × B) for the anode terminal, with a 2.44 mm wide thermal relief gap (C) and 1.15 mm solder mask opening (D). The metal cathode base must be soldered to a solid copper pour or thermal pad ≥25 mm², ideally connected via multiple vias to internal ground planes. This layout ensures the MXPLAD36KP48A achieves its rated 1.0 °C/W RθJC and 36 kW surge capability without localized overheating.