Fixed Inductors

Image	Part Number	Description / PDF
	L04021R2AHN Elco (AVX)	FIXED IND 1.2NH 400MA 200 MOHM
	L06035R6DFWTR Elco (AVX)	FIXED IND 5.6NH 300MA 250 MOHM
	L06032R7AHLTR Elco (AVX)	FIXED IND 2.7NH 750MA 80 MOHM
	L04022R7BHLTR Elco (AVX)	FIXED IND 2.7NH 250MA 250 MOHM
	L04023R3BHLTR Elco (AVX)	FIXED IND 3.3NH 250MA 400 MOHM
	L0603120JFWTR Elco (AVX)	FIXED IND 12NH 300MA 500 MOHM
$L08058R2DEWTR\3$	L08058R2DEWTR\3 Elco (AVX)	FIXED IND 8.2NH 750MA 120 MOHM
	L04021R2BHLTR Elco (AVX)	FIXED IND 1.2NH 400MA 200 MOHM
	L0402R82AHN Elco (AVX)	FIXED IND 0.82NH 500MA 60 MOHM
	L04021R5AHN Elco (AVX)	FIXED IND 1.5NH 400MA 200 MOHM
	L06031R5AHLTR Elco (AVX)	FIXED IND 1.5NH 1A 60 MOHM SMD
	L0603120FHLTR Elco (AVX)	FIXED IND 12NH 300MA 500 MOHM
	L06032R2CFWTR Elco (AVX)	FIXED IND 2.2NH 1A 80 MOHM SMD
	L04021R0AHN Elco (AVX)	FIXED IND 1NH 500MA 150 MOHM SMD
	L04023R9BHLTR Elco (AVX)	FIXED IND 3.9NH 250MA 450 MOHM
	L06038R2CFWTR Elco (AVX)	FIXED IND 8.2NH 300MA 350 MOHM
	L06031R2AHLTR Elco (AVX)	FIXED IND 1.2NH 1A 40 MOHM SMD
	L06033R3BHLTR Elco (AVX)	FIXED IND 3.3NH 750MA 80 MOHM
	L0603120GFWTR Elco (AVX)	FIXED IND 12NH 300MA 500 MOHM
	L04024R7BHLTR Elco (AVX)	FIXED IND 4.7NH 250MA 450 MOHM

Fixed Inductors

1. Overview

Fixed inductors are passive electronic components designed to store energy in magnetic fields when electrical current flows through them. Unlike variable inductors, their inductance values remain constant during operation. These components play critical roles in filtering, signal processing, energy storage, and electromagnetic interference (EMI) suppression across modern electronics, including power supplies, communication systems, and automotive electronics.

2. Main Types and Functional Classification

Type	Functional Characteristics	Application Examples
Wirewound Inductors	High precision, high current handling, low resistance	Power supplies, DC-DC converters
Chip Inductors	Compact SMD package, stable performance at high frequencies	Mobile devices, RF circuits
Ferrite Bead Inductors	Effective high-frequency noise suppression	EMI filtering in digital circuits
Thin-Film Inductors	Ultra-compact, high Q-factor, tight tolerance	5G communication modules, IoT devices

3. Structure and Composition

Typical fixed inductors consist of:

Magnetic Core: Made from ferrite, powdered iron, or composite materials to concentrate magnetic flux
Coil Structure: Copper wire wound around the core (enamelled or silver-plated)
Encapsulation: Molded resin or ceramic coating for mechanical protection and insulation
Terminations: Solder-coated ends for PCB mounting (for SMD types) or leaded connections

4. Key Technical Specifications

Parameter	Description	Importance
Inductance (L)	Measured in henrys (H), determines energy storage capacity	Defines filtering/energy storage performance
Rated Current (I_rated)	Maximum DC current before saturation	Prevents core saturation and failure
DC Resistance (DCR)	Resistance of coil windings	Affects efficiency and thermal performance
Self-Resonant Frequency (SRF)	Frequency where inductor behaves as capacitor	Limits effective operating frequency range
Q Factor	Quality factor indicating efficiency	Higher Q = lower energy losses

5. Application Fields

Consumer Electronics: Smartphones, laptops, LED drivers
Industrial Equipment: Motor drives, power inverters
Automotive Systems: ECU modules, EV battery management
Telecom Infrastructure: Base station filters, optical transceivers

6. Leading Manufacturers and Products

Manufacturer	Representative Product	Key Features
Murata	LQH3NPN100M	10 H, 1.2A, 1.8 1.4mm chip inductor
TDK	MLZ2012A100T	100MHz SRF, 1.0 1.25mm for RF circuits
Vishay	IHLP2525CZER1R0M	1 H, 12A, composite construction
Coilcraft	0402DC-103J	10 H, 5% tolerance, ultra-low profile

7. Selection Guidelines

Key considerations during selection:

Calculate required inductance based on switching frequency and ripple current
Verify rated current exceeds maximum operating current by 20-30%
Select SRF higher than circuit operating frequency
Consider package size vs. thermal dissipation requirements
For EMI suppression: Choose ferrite beads with impedance curves matching target frequencies

8. Industry Trends

Current development trends include:

Miniaturization: Sub-0.5mm size inductors for wearable devices
High-Frequency Operation: Components supporting >10GHz 5G applications
Integrated Solutions: Combined inductor-filter modules
Material Innovation: Nanocrystalline cores for higher saturation flux
Automotive Focus: AEC-Q qualified parts for EV/HEV systems