Fixed Inductors

Part Number	Description / PDF	Quantity
30121BC Murata Power Solutions	FIXED IND 114NH 37A 0.42 MOHM	0
34472C Murata Power Solutions	FIXED IND 4.7UH 1.3A 100 MOHM	0
84332C Murata Power Solutions	FIXED IND 3.3UH 1.5A 120 MOHM	532
84225C Murata Power Solutions	FIXED IND 2.2MH 50MA 45 OHM SMD	4006
47221SC Murata Power Solutions	FIXED IND 220UH 800MA 629 MOHM	659
38H302C Murata Power Solutions	FIXED IND 3UH 4.9A 19.4 MOHM SMD	0
12LRS224C Murata Power Solutions	FIXED IND 220UH 780MA 540 MOHM	0
23S221C Murata Power Solutions	FIXED IND 220UH 250MA 2.28 OHM	0
472R2C Murata Power Solutions	FIXED IND 2.2UH 6.8A 13.7 MOHM	0
34682C Murata Power Solutions	FIXED IND 6.8UH 1A 150 MOHM SMD	0
19R473C Murata Power Solutions	FIXED IND 47UH 3.4A 38 MOHM TH	0
27474C Murata Power Solutions	FIXED IND 470UH 160MA 6.5 OHM	0
481R0SC Murata Power Solutions	FIXED IND 1UH 10A 6 MOHM SMD	65
34683C Murata Power Solutions	FIXED IND 68UH 350MA 1.05 OHM	0
33221C Murata Power Solutions	FIXED IND 220UH 1.6A 102 MOHM TH	0
236R8C Murata Power Solutions	FIXED IND 6.8UH 1.22A 102 MOHM	0
29105C Murata Power Solutions	FIXED IND 1MH 180MA 4.1 OHM SMD	690
36401C Murata Power Solutions	FIXED IND 400NH 14.5A 4 MOHM SMD	985
47470C Murata Power Solutions	FIXED IND 47UH 1.47A 298 MOHM	0
28155C Murata Power Solutions	FIXED IND 1.5MH 410MA 2.62 OHM	269

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