Fixed Inductors

Image	Part Number	Description / PDF	Quantity	Rfq
	29L683C Murata Power Solutions	FIXED IND 68UH 530MA 307 MOHM	0
	47680SC Murata Power Solutions	FIXED IND 68UH 1.6A 210 MOHM	0
	29L334C Murata Power Solutions	FIXED IND 330UH 300MA 1.67 OHM	0
	29L474C Murata Power Solutions	FIXED IND 470UH 220MA 2.41 OHM	0
	35501C Murata Power Solutions	FIXED IND 500NH 11.5A 7 MOHM SMD	0
	42183C Murata Power Solutions	FIXED IND 17.6UH 10.9A 11.6 MOHM	0
	47331SC Murata Power Solutions	FIXED IND 330UH 700MA 940 MOHM	0
	80306C Murata Power Solutions	FIXED IND 220UH 3A 100 MOHM TH	0
	28224C Murata Power Solutions	FIXED IND 220UH 1.2A 381 MOHM	0
	18684C Murata Power Solutions	FIXED IND 680UH 530MA 630 MOHM	0
	41151C Murata Power Solutions	FIXED IND 150UH 1.16A 247 MOHM	0
	29L472C Murata Power Solutions	FIXED IND 4.7UH 2.2A 31 MOHM SMD	0
	18474C Murata Power Solutions	FIXED IND 470UH 600MA 465 MOHM	0
	34L683C Murata Power Solutions	FIXED IND 68UH 280MA 2.13 OHM	0
	29L223C Murata Power Solutions	FIXED IND 22UH 1.05A 114 MOHM	0
	29L103C Murata Power Solutions	FIXED IND 10UH 1.55A 64 MOHM SMD	0
	42422C-R Murata Power Solutions	FIXED IND 4.23UH 11.4A 5.2 MOHM	0
	42183C-R Murata Power Solutions	FIXED IND 17.6UH 10.9A 11.6 MOHM	0
	34L152C Murata Power Solutions	FIXED IND 1.5UH 1.65A 85 MOHM	0
	41150C Murata Power Solutions	FIXED IND 15UH 4A 28 MOHM SMD	0

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