Fixed Inductors

Image	Part Number	Description / PDF	Quantity	Rfq
	34L122C Murata Power Solutions	FIXED IND 1.2UH 1.7A 75 MOHM	0
	35251C Murata Power Solutions	FIXED IND 250NH 15.5A 4.5 MOHM	0
	34L332C Murata Power Solutions	FIXED IND 3.3UH 1A 150 MOHM SMD	0
	18153C Murata Power Solutions	FIXED IND 15UH 3A 18 MOHM TH	0
	18333C Murata Power Solutions	FIXED IND 33UH 2A 40 MOHM TH	0
	42422C Murata Power Solutions	FIXED IND 4.23UH 11.4A 5.2 MOHM	0
	29L105C Murata Power Solutions	FIXED IND 1MH 140MA 6.48 OHM SMD	0
	47330SC Murata Power Solutions	FIXED IND 33UH 2.2A 91.1 MOHM	0
	35801C Murata Power Solutions	FIXED IND 800NH 9.5A 10 MOHM SMD	0
	41470C Murata Power Solutions	FIXED IND 47UH 2.2A 62 MOHM SMD	0
	29L152C Murata Power Solutions	FIXED IND 1.5UH 4.2A 15 MOHM	0
	28473C Murata Power Solutions	FIXED IND 47UH 2.66A 86 MOHM SMD	0
	29L473C Murata Power Solutions	FIXED IND 47UH 800MA 223 MOHM	0
	18254C Murata Power Solutions	FIXED IND 250UH 800MA 255 MOHM	0
	42652C-R Murata Power Solutions	FIXED IND 6.5UH 12.4A 6 MOHM	0
	18683C Murata Power Solutions	FIXED IND 68UH 1.35A 70 MOHM TH	0
	43402C-R Murata Power Solutions	FIXED IND 4UH 22.4A 3.1 MOHM	0
	29L102C Murata Power Solutions	FIXED IND 1UH 4.6A 13 MOHM SMD	0
	40150C Murata Power Solutions	FIXED IND 15UH 2.4A 30 MOHM SMD	0
	42132C-R Murata Power Solutions	FIXED IND 1.27UH 14.3A 2.5 MOHM	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