Microchip Technology MPLAD18KP28CA

Overview

MPLAD18KP28CA from Microsemi is a bidirectional surface-mount transient voltage suppressor (TVS) designed for high-energy surge protection in aerospace, automotive, and industrial power 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 MPLAD18KP28CA datasheet, MPLAD18KP28CA pinout, MPLAD18KP28CA application, or MPLAD18KP28CA equivalent, key selection criteria include its bidirectional polarity, 28 V working voltage, 45.5 V max clamping at 396 A, thermal resistance of 0.7 °C/W junction-to-case, and compliance with IEC 61000-4-5 (Class 1–4, 2–42 Ω source) and DO-160F lightning standards.

Technical Context

This TVS diode operates as a voltage-clamped crowbar device triggered by avalanche breakdown, with symmetrical bidirectional conduction enabling protection against both positive and negative transients without polarity sensitivity. Its low R_θJC (0.7 °C/W) and metal-base cathode construction optimize heat transfer to PCB copper or heatsink, supporting multi-stroke surge endurance per RTCA DO-160 Section 22.

It is characterized using standardized 10/1000 μs double-exponential waveforms and validated for secondary lightning protection across 2 Ω, 12 Ω, and 42 Ω source impedances per IEC 61000-4-5, with full surge testing performed at 1000 A due to equipment limits - consistent with its rated 396 A IPP.

Key Specifications

Pinout & Package

Package: Surface-mount PLAD (Plastic Leaded Anodeless Diode), void-free UL94V-0 epoxy body with metal base cathode; dimensions 12.32 × 10.54 × 5.08 mm (L × W × H); weight ≈1 g; RoHS-compliant matte-tin plating.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMBJ28CA and SMCJ28CA, MPLAD18KP28CA provides 30× and 12× higher peak pulse power respectively, enabling certified lightning protection in safety-critical aerospace and transportation systems where lower-rated TVS devices would fail catastrophically under DO-160 or ISO 7637-2 test conditions.

Availability

MPLAD18KP28CA is available at Aetrix Electronics and suitable for aerospace avionics power bus protection, automotive 28 V load dump mitigation, and industrial motor drive DC link surge suppression requiring stable component supply across extended production lifecycles.

Supply support for MPLAD18KP28CA 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 radiation-hardened ICs for aerospace, defense, and industrial markets.

The MPLAD family was engineered specifically for high-energy transient suppression in mission-critical platforms, emphasizing thermal robustness, multi-stroke endurance, and compliance with RTCA DO-160, IEC 61000-4-5, and AEC-Q101 standards.

FAQ

What is the clamping voltage of MPLAD18KP28CA at its rated peak pulse current?

The MPLAD18KP28CA has a maximum clamping voltage (V_C) of 45.5 V at its rated peak pulse current of 396 A under 10/1000 μs waveform conditions. This value is guaranteed across temperature and production lots, ensuring predictable overvoltage limiting for downstream 28 V systems. The clamping performance is verified per Figure 3 in RF01215 Rev B and forms the basis for system-level surge margin calculations in MPLAD18KP28CA designs.

Is MPLAD18KP28CA compliant with automotive reliability standards?

Yes, MPLAD18KP28CA is qualified to AEC-Q101 for discrete semiconductors, covering temperature cycling, humidity, mechanical shock, and surge testing relevant to automotive under-hood and powertrain environments. Its 28 V VWM and 45.5 V clamping align with ISO 7637-2 Pulse 5a/b load dump requirements, and its bidirectional construction supports dual-polarity protection in 24–28 V vehicle architectures without additional components.

How does the metal base cathode configuration affect PCB layout for MPLAD18KP28CA?

The metal base of MPLAD18KP28CA serves as the cathode terminal and primary thermal path, requiring direct soldering to a large copper pour or heatsink. Layout must follow the recommended pad dimensions (12.32 × 10.54 mm) with thermal vias to inner ground planes. Improper thermal anchoring increases junction temperature, reducing surge endurance and violating the 0.7 °C/W R_θJC spec - a critical design constraint explicitly called out in RF01215 Rev B for MPLAD18KP28CA reliability.

Can MPLAD18KP28CA be used for IEC 61000-4-5 Class 5 lightning protection?

No, MPLAD18KP28CA is rated for IEC 61000-4-5 Class 1–4 with 42 Ω source impedance and Class 2–3 with 2 Ω source impedance, but not Class 5. Per RF01215 Rev B, Class 5 compliance is limited to MPLAD18KP7.0A–130CA variants. Using MPLAD18KP28CA in Class 5 applications exceeds its validated surge energy envelope and voids compliance - designers must select lower-VWM variants or verify alternate test data before deployment.

What is the moisture sensitivity level (MSL) of MPLAD18KP28CA?

MPLAD18KP28CA has a moisture sensitivity level (MSL) of Level 1 per IPC/JEDEC J-STD-020B, meaning it is not moisture-sensitive and requires no dry pack or baking prior to reflow soldering. This simplifies manufacturing logistics and eliminates floor-life constraints - a key advantage for high-reliability production of MPLAD18KP28CA in aerospace and industrial assembly lines.