Monolithic Power Systems Inc. MPL-AL4020-4R7

Overview

MPL-AL4020-4R7 from Monolithic Power Systems is a low-resistance molded power inductor with 4.7 µH nominal inductance (±20%), 52.2 mΩ typical DCR, 3.65 A rated current (ΔT = 40 K), and 4.2 A saturation current at both 25°C and 100°C ambient. It operates from –40°C to +155°C and is optimized for high-current, high-frequency DC-DC converters in FPGA and POL applications.

For engineers reviewing the MPL-AL4020-4R7 datasheet, MPL-AL4020-4R7 pinout (two-terminal SMT device), MPL-AL4020-4R7 application in point-of-load regulation, or MPL-AL4020-4R7 equivalent for low-DCR molded inductors, this page delivers verified electrical specs, thermal behavior context, package dimensions, and real-world selection guidance.

Technical Context

This molded inductor uses composite powder core technology enabling soft saturation behavior and stable inductance over temperature. Its 4.7 µH value is measured at 100 kHz/100 mA, with resonance frequency of 21 MHz - supporting operation in switching supplies up to ~5 MHz without significant impedance roll-off.

The 4.1 mm × 4.1 mm × 1.9 mm footprint integrates into compact layouts while maintaining low AC losses and minimal audible noise. Thermal performance is characterized on a single-layer 30 mm × 50 mm PCB with 35 µm copper, where IR rating reflects ΔT = 40 K under defined test conditions.

Key Specifications

Pinout & Package

Package: Molded SMT inductor, 4.1 mm × 4.1 mm × 1.9 mm (L×W×H), two-terminal land pattern with top marking "4R7" and dot indicating start of winding.

Key Features

Applications

Availability

MPL-AL4020-4R7 is available at Aetrix Electronics and suitable for battery-powered devices, FPGA power delivery, and high-current SMPS requiring stable component supply, consistent thermal performance, and RoHS/REACH-compliant materials.

Supply support for MPL-AL4020-4R7 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

Monolithic Power Systems (MPS) is a fabless semiconductor company specializing in high-performance power management ICs and passive components, headquartered in Kirkland, WA.

The MPL-AL series targets high-efficiency, high-density DC-DC conversion, with the AL4020 variant engineered specifically for low-DCR, high-saturation-current applications in space-constrained POL and FPGA power stages.

FAQ

What is the thermal test condition used for the rated current (IR) specification?

The rated current of 3.65 A causes a 40 K temperature rise when mounted on a single-layer 30 mm × 50 mm PCB with 35 µm copper thickness. Actual thermal performance varies with PCB stack-up, copper area, airflow, and proximity to heat sources - design validation under target layout is required.

Does MPL-AL4020-4R7 have polarity or winding direction sensitivity?

Yes - Terminal 1 is marked with a dot on the top surface and denotes the start of winding. While not electrically polarized, consistent orientation improves magnetic field containment in multi-inductor layouts and simplifies EMI filtering design.

How does the 30% inductance drop define saturation current?

Saturation current (ISAT) is the DC bias level at which inductance falls by 30% from its zero-bias value, measured at 25°C or 100°C ambient. For MPL-AL4020-4R7, ISAT is 4.2 A at both temperatures - indicating robust core material stability across operating range.

Can this inductor be used in a 5 MHz switching converter?

Its 21 MHz typical self-resonant frequency provides usable impedance up to ~5 MHz, but core losses increase significantly above 3 MHz. Efficiency and temperature rise must be validated experimentally at 5 MHz; MPS recommends lower-L variants (e.g., MPL-AL4020-2R2) for such high-frequency use.

Is the MPL-AL4020-4R7 halogen-free and RoHS-compliant?

Yes - it meets RoHS Directive 2011/65/EU and REACH Regulation (EC) No. 1907/2006, and is certified halogen-free per IEC 61249-2-21. Full compliance documentation is available via MPS Quality Assurance portal.

What is the recommended land pattern per the datasheet?

The official land pattern specifies 3.40 mm × 3.40 mm pads with 0.50 mm solder mask opening, spaced 2.40 mm center-to-center. Thermal relief vias under the pad are discouraged due to mechanical stress risk; instead, use peripheral thermal vias connected to internal ground planes.