Fixed Inductors

Part Number	Description / PDF	Quantity
49150SC Murata Power Solutions	FIXED IND 15UH 4.4A 27 MOHM SMD	391
27153C Murata Power Solutions	FIXED IND 15UH 900MA 230 MOHM	0
15473C Murata Power Solutions	FIXED IND 47UH 4.04A 45.6 MOHM	0
26221C Murata Power Solutions	FIXED IND 220UH 660MA 730 MOHM	0
29683C Murata Power Solutions	FIXED IND 68UH 650MA 250 MOHM	0
29474C Murata Power Solutions	FIXED IND 470UH 260MA 1.6 OHM	0
82682C Murata Power Solutions	FIXED IND 6.8UH 640MA 270 MOHM	2567
232R2C Murata Power Solutions	FIXED IND 2.2UH 2.1A 40 MOHM SMD	0
23S680C Murata Power Solutions	FIXED IND 68UH 450MA 641 MOHM	0
12LRS473C Murata Power Solutions	FIXED IND 47UH 1.7A 140 MOHM TH	186
48151SC Murata Power Solutions	FIXED IND 150UH 1.35A 280 MOHM	328
49331SC Murata Power Solutions	FIXED IND 330UH 900MA 550 MOHM	450
18R682C Murata Power Solutions	FIXED IND 6.8UH 4.15A 12 MOHM	0
27T102C Murata Power Solutions	FIXED IND 1UH 2A 80 MOHM SMD	0
12LRS156C Murata Power Solutions	FIXED IND 15MH 95MA 37 OHM TH	0
49330SC Murata Power Solutions	FIXED IND 33UH 2.9A 60 MOHM SMD	5
266R8C Murata Power Solutions	FIXED IND 6.8UH 3.1A 54 MOHM	0
11R224C Murata Power Solutions	FIXED IND 220UH 240MA 2.4 OHM TH	2402
38S451C Murata Power Solutions	FIXED IND 450NH 16A 2.6 MOHM SMD	0
38H801C Murata Power Solutions	FIXED IND 800NH 10.5A 5 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