Power Inductors — Shielded, Unshielded, High-Current and Low-DCR

Power inductors are the energy-storage and filtering workhorses of switched-mode power supplies, storing energy in their magnetic field during each switching cycle and releasing it to the load. They appear in DC-DC converters, voltage regulator modules (VRMs), point-of-load (POL) regulators, LED drivers and power-factor correction stages, where their inductance, saturation current and DC resistance (DCR) directly determine efficiency, ripple and thermal performance. ADD Components is a professional electronic components distributor supplying shielded, unshielded, high-current and low-DCR power inductors in both SMD and through-hole packages from TDK, Murata, Wurth Elektronik, Eaton and Vishay. This guide reviews the principal power inductor types, the key selection parameters and representative part numbers for teams buying power inductors online.

Product Types

Shielded Power Inductors

Shielded power inductors enclose the coil in a magnetic shield — a ferrite or metal-composite shell — that contains the flux and reduces electromagnetic interference (EMI) with nearby components and traces. They are the preferred choice in dense, noise-sensitive designs such as smartphones, point-of-load regulators and automotive electronics, where the smaller radiated field allows tighter component placement. TDK's VLS series, Wurth's WE-PD series and Vishay's IHLP series are leading shielded families that ADD Components supplies in volume.

Unshielded (Semi-Shielded) Power Inductors

Unshielded power inductors use an open wirewound construction on a drum core, with the winding visible and the flux partially exposed. They cost less than shielded parts and can deliver higher saturation current for a given size, but they radiate more flux and may require careful spacing from sensitive circuitry. Unshielded and semi-shielded parts are widely used in consumer power adapters, LED drivers and general-purpose converters where cost and size dominate. Murata's LQH families and many TDK VLS and Wurth wirewound parts fall into this category.

High-Current and Low-DCR Inductors

High-current power inductors use thick wire, flat-wire or metal-composite cores to minimise DCR and maximise saturation current. Lower DCR reduces I²R loss and self-heating, directly improving converter efficiency at heavy loads, while higher saturation current keeps inductance stable under peak current. Metal-composite and flat-wire designs — such as TDK's SPM series, Eaton's HCMA series and Wurth's WE-HCI series — are favoured for high-efficiency DC-DC converters, servers and GPU/CPU power delivery where thermal margins are tight.

SMD and Through-Hole Power Inductors

Surface-mount (SMD) power inductors dominate modern high-volume production, with footprints from 2.0 x 1.6 mm to 12 x 12 mm and beyond. They suit reflow assembly and compact switching regulators, while through-hole power inductors remain common in higher-power, lower-density designs such as industrial power supplies, audio amplifiers and legacy or ruggedised equipment. ADD Components sources both styles, helping customers match footprint, height and current rating to their PCB and assembly process.

Metal Composite (High-Saturation) Inductors

Metal composite power inductors press a mixture of metal powder and binder around the coil to create a soft-saturation core with low loss and excellent thermal stability. They combine shielding, low DCR and high saturation current in a compact package, making them ideal for high-frequency, high-efficiency regulators. Representative families include TDK's SPM series and Vishay's IHLP series, both of which our team can source in production quantities.

Key Selection Parameters

• Inductance and Tolerance: Typical values range from 0.47 µH to several hundred µH; confirm value and tolerance (±20% or ±30% are common for power parts).

• Saturation Current (Isat): The current at which inductance falls by a specified percentage (usually 20% or 30%) — must exceed the peak converter current.

• Rated / Thermal Current (Irms): The DC current that produces a specified temperature rise, often 40°C.

• DCR: Lower DC resistance reduces conduction loss and self-heating; critical for high-efficiency and high-current designs.

• Shielding: Shielded parts for EMI-sensitive layouts, unshielded for cost-driven or less dense boards.

• Package and Footprint: SMD sizes (e.g., 2520, 3015, 5045) versus through-hole; confirm height limits and pick-and-place compatibility.

• Switching Frequency: Match the inductor's self-resonant frequency and core-loss profile to the converter's switching frequency.

• Operating Temperature: Verify the rated range against ambient and self-heating, especially in automotive and industrial applications.

Representative Inductors We Source

Send Us Your Inductor Requirements

ADD Components is a Hong Kong-based electronic components distributor supplying power inductors to OEM, EMS and contract manufacturing customers across the region and worldwide. We hold and source TDK VLS and SPM, Murata LQH, Wurth Elektronik WE-PD and WE-HCI, Eaton DRQ and HCMA, and Vishay IHLP families, covering shielded, unshielded, high-current and low-DCR parts in SMD and through-hole packages. Every reel ships with factory traceability, date-code verification and anti-counterfeit screening.

Send your part numbers, target pricing or full bill of materials to Info@addcomponents.hk for a same-day quotation. We support spot buys, blanket orders and power inductor wholesale programs, and we can recommend pin-compatible alternatives to consolidate your BOM and shorten lead times.

Email: Info@addcomponents.hk | Tel: +852 5334 3091 | WhatsApp: +852 5334 3091

Back to Inductor Guide