Microchip Technology MAPLAD18KP85CAE3

Overview

MAPLAD18KP85CAE3 from Microsemi is a bidirectional surface-mount transient voltage suppressor (TVS) designed for high-energy surge protection in aerospace and automotive systems. It delivers 18,000 W peak pulse power at 10/1000 μs, features 85 V reverse standoff voltage (VWM), clamps to ≤137 V at 1000 A IPP, and operates across –55°C to +150°C junction temperature. It is qualified to AEC-Q101 and meets RTCA DO-160F Level 4 pin injection for Waveform 4.

For engineers reviewing the MAPLAD18KP85CAE3 datasheet, MAPLAD18KP85CAE3 pinout, MAPLAD18KP85CAE3 application, or MAPLAD18KP85CAE3 equivalent, key selection criteria include its bidirectional polarity, 0.7°C/W junction-to-case thermal resistance, RoHS-compliant e3 plating, IEC 61000-4-5 Class 2–5 secondary lightning compliance, and suitability for multi-stroke lightning protection per DO-160 Section 22.

Technical Context

This TVS diode uses an avalanche breakdown mechanism to clamp transients, with breakdown voltage V(BR) specified at 94.4–104.0 V under 5 mA test current. Its low RθJC (0.7°C/W) enables efficient heat transfer to the PCB copper pad or heatsink, critical for sustaining repeated 18 kW surges at ≤0.05% duty cycle.

The device supports both unidirectional and bidirectional configurations - MAPLAD18KP85CAE3 is explicitly bidirectional (CA suffix), with symmetrical clamping behavior and cathode marked on the metal base. It 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

MAPLAD18KP85CAE3 uses a surface-mount PLAD package with a metal base acting as the cathode terminal for both polarities. The device has two terminals: anode and cathode, with polarity marked on the metal bottom surface. Recommended pad layout per RF01215 Rev B specifies 12.32–12.57 mm length (A1), 10.54–10.80 mm width (A2), and 3.68–3.94 mm terminal width (B).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMBJ85CA and SMCJ85CA, MAPLAD18KP85CAE3 provides 30× higher peak pulse power and 7× lower thermal resistance - enabling certified lightning protection in safety-critical avionics, whereas alternatives serve only basic industrial or automotive surge suppression.

Availability

MAPLAD18KP85CAE3 is available at Aetrix Electronics and suitable for avionics power distribution, automotive ECU protection, and industrial motor drive I/O requiring stable component supply with full traceability and long-lifecycle support.

Supply support for MAPLAD18KP85CAE3 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, mixed-signal, and radiation-hardened ICs for aerospace, defense, and industrial markets.

The PLAD family was engineered specifically for high-energy transient suppression in safety-critical platforms - emphasizing thermal robustness, multi-stroke endurance, and regulatory compliance for DO-160, AEC-Q101, and IEC 61000-4-x standards.

FAQ

What does the 'CA' suffix indicate in MAPLAD18KP85CAE3?

The 'CA' suffix in MAPLAD18KP85CAE3 denotes bidirectional construction, meaning the device clamps transients of either polarity symmetrically. Unlike unidirectional variants (e.g., MAPLAD18KP85AE3), it has no inherent anode/cathode orientation for surge direction - both terminals behave identically under reverse or forward surge conditions, making it ideal for AC-coupled or differential signal lines.

Is MAPLAD18KP85CAE3 qualified to AEC-Q101 and DO-160F?

Yes, MAPLAD18KP85CAE3 is fully qualified to AEC-Q101 for automotive reliability and tested per RTCA DO-160F Section 22 for multi-stroke lightning. It achieves Level 4 pin injection immunity for Waveform 4 (6.4/69 μs) and meets IEC 61000-4-5 Class 2–5 secondary lightning protection - all verified in Microsemi's RF01215 Rev B documentation.

What is the thermal design requirement for MAPLAD18KP85CAE3 to sustain 18,000 W surges?

To sustain repeated 18,000 W surges, MAPLAD18KP85CAE3 requires mounting on a minimum 12.3 mm × 10.5 mm copper pad per RF01215 Rev B, with thermal vias to inner ground planes. Its 0.7°C/W RθJC demands direct conduction to PCB copper - ambient derating begins above 100°C case temperature, and steady-state dissipation is limited to 71 W only when TC is actively held at 100°C via heatsink.

How does the clamping voltage of MAPLAD18KP85CAE3 compare to its standoff voltage?

MAPLAD18KP85CAE3 has a reverse standoff voltage (VWM) of 85 V and a maximum clamping voltage (VC) of 137 V at 1000 A IPP. This 61% overvoltage margin ensures protected circuits remain below absolute maximum ratings during worst-case transients - critical for safeguarding 100 V-rated op-amps or FPGAs in avionics power supplies.

What packaging and marking details apply to MAPLAD18KP85CAE3?

MAPLAD18KP85CAE3 ships in RoHS-compliant e3 matte-tin plating, with body marking of the full part number. It is available in bulk or EIA-481-B tape-and-reel (add "TR" suffix). The metal base is the cathode and must be soldered to a thermally optimized pad; polarity is indicated by cathode marking on the bottom surface, not silkscreen.