Monolithic Power Systems Inc. MPL-AL4020-2R2

Overview

MPL-AL4020-2R2 from Monolithic Power Systems is a low-resistance molded power inductor with 2.2 µH nominal inductance, 21.5 mΩ typical DCR, 5.5 A rated current (ΔT = 40 K), and 6.2 A saturation current at both 25°C and 100°C. 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-AL4020-2R2 datasheet, MPL-AL4020-2R2 pinout (though unpinned, as a two-terminal passive), MPL-AL4020-2R2 application in high-current SMPS, or MPL-AL4020-2R2 equivalent for low-DCR molded inductors, this page delivers verified electrical specs, thermal behavior, package dimensions, and design-critical performance trade-offs including soft saturation and low audible noise.

Technical Context

This molded inductor uses composite powder core technology enabling stable inductance over temperature and soft saturation characteristics-critical for maintaining regulation during transient load steps in point-of-load converters. Its 4.1 mm × 4.1 mm × 1.9 mm footprint supports high-density PCB layouts while minimizing AC losses at switching frequencies up to 37 MHz resonance.

The device's low 21.5 mΩ typical DCR reduces conduction loss in high-current paths, and its +155°C max operating temperature (including self-heating) allows reliable operation in thermally constrained embedded computing and battery-powered systems without derating under typical board-level thermal conditions.

Key Specifications

Pinout & Package

As a two-terminal surface-mount molded inductor, MPL-AL4020-2R2 has no active pins or signal assignments. It features a symmetric land pattern with two solderable terminals (anode and cathode indistinguishable), marked with a dot indicating start of winding. Package is non-leaded, fully encapsulated molded construction measuring 4.1 mm × 4.1 mm × 1.9 mm (L × W × H).

Key Features

Applications

Availability

MPL-AL4020-2R2 is available at Aetrix Electronics and suitable for battery-powered devices, FPGA core power delivery, and high-current SMPS requiring stable component supply, consistent thermal performance, and RoHS/REACH-compliant materials.

Supply support for MPL-AL4020-2R2 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, with global design and support centers.

The MPL-AL series is engineered specifically for high-efficiency, high-density DC-DC conversion in space-constrained and thermally demanding applications-including embedded computing, telecom infrastructure, and portable electronics.

FAQ

What is the thermal test condition used to specify rated current?

The rated current (5.5 A) is defined as the DC current causing a 40 K temperature rise when mounted on a single-layer 30 mm × 50 mm PCB with 35 µm copper thickness. Actual thermal performance depends on PCB layout, copper area, airflow, and proximity to heat sources-designers should validate with thermal imaging under worst-case load.

Does MPL-AL4020-2R2 have polarity marking, and why does it matter?

Yes-it features a dot marking indicating the start of winding. While functionally non-polarized in most buck applications, polarity matters in coupled-inductor topologies or EMI filter designs where winding direction affects common-mode rejection and magnetic coupling; incorrect orientation may degrade noise suppression.

How does soft saturation benefit transient response in POL converters?

Soft saturation causes gradual inductance reduction (30% at 6.2 A) rather than abrupt collapse, allowing control loops to remain stable during fast load steps (e.g., FPGA core wake-up). This avoids output voltage droop exceeding specification limits and prevents false overcurrent triggering in current-mode controllers.

Can MPL-AL4020-2R2 replace traditional drum-core inductors in 2 MHz designs?

Yes-its 37 MHz self-resonant frequency and low AC losses make it suitable for 2 MHz operation. Unlike drum-core inductors, its molded construction suppresses fringing fields and mechanical vibration, reducing radiated EMI and audible noise-key advantages in high-frequency, low-profile POL layouts.

Is the +155°C maximum operating temperature inclusive of self-heating?

Yes-the specification explicitly states "–40°C to +155°C (including temp rise)", meaning the sum of ambient temperature and self-heating must not exceed +155°C. At full 5.5 A load, measured temperature rise is ~40 K, permitting safe operation up to +115°C ambient in sealed enclosures.

What does "RoHS/REACH-compliant, halogen-free" mean for manufacturing compliance?

This confirms MPL-AL4020-2R2 contains no lead, mercury, cadmium, hexavalent chromium, PBB, PBDE, or restricted phthalates per EU directives, and zero brominated/chlorinated flame retardants-ensuring compatibility with lead-free reflow profiles and meeting environmental requirements for global electronics markets including automotive and medical.