Microchip Technology MAPLAD18KP75CA

Overview

MAPLAD18KP75CA from Microsemi is a bidirectional surface-mount transient voltage suppressor (TVS) designed for high-energy surge protection in aerospace, automotive, and industrial systems. It delivers 18,000 W peak pulse power at 10/1000 μs, clamps at ≤121 V under 100 A impulse current, and features a 75 V reverse standoff voltage (VWM) with ±5% breakdown tolerance (83.3–92.1 V). It meets RTCA DO-160F Level 4 pin injection (Waveform 4) and IEC 61000-4-5 Class 1–4 secondary lightning protection.

For engineers reviewing the MAPLAD18KP75CA datasheet, MAPLAD18KP75CA pinout, MAPLAD18KP75CA application, or MAPLAD18KP75CA equivalent, this device is selected for high-reliability DC bus, avionics power input, and 24–48 V vehicle ECU protection where multi-stroke lightning immunity, low thermal resistance (RθJC = 0.7 °C/W), and RoHS-compliant SMT mounting are critical design requirements.

Technical Context

The MAPLAD18KP75CA employs an avalanche diode structure optimized for fast response (<5 ns clamping time) and high cumulative energy handling. Its metal-base package enables direct thermal coupling to PCB copper or heatsinks, supporting sustained surge duty cycles ≤0.05% per MIL-STD-750 test conditions.

It operates across –55°C to +150°C junction temperature, with standby leakage ID ≤10 μA at 75 V, and is qualified to AEC-Q101 for automotive use. Bidirectional symmetry ensures equal clamping in both polarities-critical for AC-coupled signal lines and ungrounded DC rails subject to polarity-reversal transients.

Key Specifications

Pinout & Package

MAPLAD18KP75CA uses a surface-mount, metal-base PLAD package (0.470″ × 0.230″ × 0.100″) with cathode and anode terminals on opposite sides of the molded body. The metal base serves as the cathode for unidirectional variants; for bidirectional MAPLAD18KP75CA, both terminals are symmetrical and non-polarized.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMBJ75CA and SMCJ75CA, MAPLAD18KP75CA provides 30× higher peak pulse power, 5× lower thermal resistance, and formal DO-160F/IEC 61000-4-5 certification-making it the only option for certified aerospace and high-reliability automotive power rail protection.

Availability

MAPLAD18KP75CA is available at Aetrix Electronics and suitable for aerospace avionics, automotive ECU power conditioning, and industrial motor drive DC link protection requiring stable component supply across long production lifecycles.

Supply support for MAPLAD18KP75CA 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, radiation-tolerant, and aerospace-grade components with deep expertise in analog, timing, and power protection solutions.

The MAPLAD18KP75CA belongs to Microsemi's PLAD family of high-power surface-mount TVS diodes, engineered specifically for certified lightning and load-dump protection in safety-critical platforms where thermal performance and multi-stroke endurance are non-negotiable.

FAQ

What is the clamping voltage of MAPLAD18KP75CA at its rated peak pulse current?

The MAPLAD18KP75CA has a maximum clamping voltage (VC) of 121 V at 100 A peak pulse current under 10/1000 μs waveform conditions. This value is guaranteed per datasheet Figure 3 and ensures downstream circuitry remains within safe operating voltage limits during standardized surge events. The MAPLAD18KP75CA achieves this with sub-5 ns response time and minimal voltage overshoot due to its low-parasitic metal-base construction.

Is MAPLAD18KP75CA qualified for automotive applications?

Yes, MAPLAD18KP75CA is qualified to AEC-Q101 for stress testing including HTRB, HTGB, and temperature cycling. Its 75 V VWM, 121 V clamping, and 10 μA leakage at rated voltage make it suitable for 24 V and 48 V automotive ECUs. The MAPLAD18KP75CA also supports optional MIL-PRF-19500 screening for mission-critical vehicle subsystems requiring full lot traceability.

Does MAPLAD18KP75CA require a heatsink for standard operation?

No external heatsink is required for MAPLAD18KP75CA under typical single-event surge conditions. Its 0.7 °C/W junction-to-case thermal resistance allows effective heat dissipation into the PCB copper plane via the metal base. However, for repetitive surges exceeding 0.05% duty cycle, thermal simulation using the provided pad layout and FR4 board stack-up is recommended to verify junction temperature stays below 150°C.

How does the bidirectional construction of MAPLAD18KP75CA affect PCB layout?

The bidirectional construction of MAPLAD18KP75CA eliminates polarity marking and orientation constraints-both terminals are functionally identical. PCB layout requires symmetric copper pour under the metal base and equal-length traces to each terminal to preserve impedance balance. Unlike unidirectional TVS devices, MAPLAD18KP75CA can be placed without regard to signal direction or ground reference, simplifying routing in differential or floating interfaces.

What certifications does MAPLAD18KP75CA meet for aerospace use?

MAPLAD18KP75CA meets RTCA DO-160F Section 22 multi-stroke lightning (Level 4 pin injection, Waveform 4) and IEC 61000-4-5 Class 1–4 secondary lightning protection (42 Ω, 12 Ω, and 2 Ω source impedances). These certifications are verified per Microsemi RF01215 Rev B test reports. The MAPLAD18KP75CA is also moisture-sensitivity Level 1 (no dry pack required) and UL94V-0 rated for flammability compliance in enclosed avionics enclosures.