Microchip Technology MAPLAD18KP120A

Overview

MAPLAD18KP120A from Microsemi is a unidirectional 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 ≤193 V under 100 A peak impulse current, and features a 120 V reverse standoff voltage (VWM) with 133–147 V breakdown range (V(BR)). It meets RTCA DO-160F Waveform 4 Level 4 and IEC 61000-4-5 Class 1–5 secondary lightning protection requirements.

For engineers reviewing the MAPLAD18KP120A datasheet, MAPLAD18KP120A pinout, MAPLAD18KP120A application, or MAPLAD18KP120A equivalent, key selection criteria include its 120 V VWM rating, 193 V max clamping voltage at IPP = 100 A, thermal resistance of 0.7 °C/W junction-to-case, RoHS-compliant e3 plating, and qualification per AEC-Q101 and MIL-PRF-19500 screening options.

Technical Context

The MAPLAD18KP120A employs an avalanche diode structure optimized for low clamping ratio and fast response (<5 ns), enabling effective suppression of lightning-induced transients and load dump events. Its metal-base cathode construction minimizes thermal resistance and supports high-reliability mounting on FR4 PCBs with recommended pad layout.

It operates across –55 °C to +150 °C junction temperature, with 3σ lot norm screening on standby current (ID ≤ 10 μA @ VWM), and complies with ESD (IEC 61000-4-2), EFT (IEC 61000-4-4), and pin injection immunity per RTCA/DO-160F Waveforms 4 and 5A.

Key Specifications

Pinout & Package

MAPLAD18KP120A uses a surface-mount plastic package with metal base cathode termination. The cathode is located on the metal bottom surface (package backside); the anode is accessible via the top-side metallized terminals. Package dimensions: 12.32 × 10.54 × 5.08 mm (L × W × H), weight ≈1 g.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMBJ120A and SMCJ120A, the MAPLAD18KP120A provides 30× and 12× higher peak pulse power respectively, enabling single-device compliance with aviation and heavy-duty automotive standards-critical when PCB area, thermal management simplicity, and multi-stroke endurance are design priorities.

Availability

MAPLAD18KP120A is available at Aetrix Electronics and suitable for aerospace avionics, automotive ECU power protection, and industrial motor drive DC bus applications requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for MAPLAD18KP120A 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 MAPLAD18KP120A belongs to Microsemi's PLAD high-power TVS family, engineered specifically for multi-stroke lightning and load dump protection in safety-critical platforms where thermal robustness and qualification pedigree are mandatory.

FAQ

What is the clamping voltage of MAPLAD18KP120A at its rated peak pulse current?

The MAPLAD18KP120A has a maximum clamping voltage (VC) of 193 V at 100 A peak pulse current (IPP) 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 surge events. The clamping performance is validated across the full operating temperature range and supports system-level immunity to IEC 61000-4-5 and RTCA DO-160F tests.

Is MAPLAD18KP120A qualified for automotive applications?

Yes, MAPLAD18KP120A is qualified to AEC-Q101 for stress testing including temperature cycling, humidity bias, and surge robustness. It is explicitly rated for automotive load dump protection and referenced in Microsemi's application guidance for engine control units and battery management systems. Its 120 V VWM and 193 V clamping align with 12 V/24 V dual-battery architectures subjected to ISO 7637-2 Pulse 5a.

Does MAPLAD18KP120A require special PCB layout considerations?

Yes, MAPLAD18KP120A requires a dedicated thermal pad layout per the manufacturer's recommended footprint: minimum 12.32 × 10.54 mm copper area on the bottom layer, connected to internal ground or thermal planes via ≥6 thermal vias. The metal base cathode must be soldered directly to this pad to achieve the specified 0.7 °C/W junction-to-case thermal resistance-failure to do so degrades surge endurance and may cause thermal failure under repeated transients.

Can MAPLAD18KP120A be used in bidirectional configurations?

No, MAPLAD18KP120A is unidirectional (denoted by "A" suffix). For bidirectional operation, the equivalent part is MAPLAD18KP120CA. The "A" version conducts only during reverse-bias surges and blocks forward current; using it in AC or bipolar signal paths would result in unintended conduction or failure. Always match polarity suffix ("A" vs "CA") to system voltage polarity requirements.

What is the moisture sensitivity level (MSL) of MAPLAD18KP120A?

MAPLAD18KP120A is rated Moisture Sensitivity Level 1 per IPC/JEDEC J-STD-020B, meaning it has unlimited floor life and does not require dry pack or baking prior to reflow soldering. This eliminates handling overhead and reduces manufacturing risk-particularly valuable in high-reliability production environments where moisture-induced popcorning must be avoided.