Fixed Inductors

Part Number	Description / PDF	Quantity
30151BC Murata Power Solutions	FIXED IND 154NH 37A 0.42 MOHM	0
11R474C Murata Power Solutions	FIXED IND 470UH 140MA 6.4 OHM TH	18321
18R103C Murata Power Solutions	FIXED IND 10UH 3.45A 15 MOHM TH	95
19R476C Murata Power Solutions	FIXED IND 47MH 110MA 36 OHM TH	160
17154C Murata Power Solutions	FIXED IND 150UH 580MA 490 MOHM	0
30850BC Murata Power Solutions	FIXED IND 85NH 37A 0.42 MOHM SMD	0
32471C Murata Power Solutions	FIXED IND 470UH 660MA 312 MOHM	0
39S103C Murata Power Solutions	FIXED IND 10UH 5A 13.5 MOHM SMD	0
22R473MC Murata Power Solutions	FIXED IND 47UH 990MA 220 MOHM	0
49221C Murata Power Solutions	FIXED IND 220UH 950MA 805 MOHM	785
18R155C Murata Power Solutions	FIXED IND 1.5MH 330MA 1.5 OHM TH	45
34105C Murata Power Solutions	FIXED IND 1MH 90MA 15 OHM SMD	0
22R475C Murata Power Solutions	FIXED IND 4.7MH 81MA 15 OHM TH	8786
27684C Murata Power Solutions	FIXED IND 680UH 140MA 8.5 OHM	0
45541C Murata Power Solutions	FIXED IND 540NH 7A 11 MOHM SMD	0
12RS473C Murata Power Solutions	FIXED IND 47UH 2.2A 100 MOHM TH	123
22R474MC Murata Power Solutions	FIXED IND 470UH 370MA 1.65 OHM	0
34152C Murata Power Solutions	FIXED IND 1.5UH 2.1A 40 MOHM	0
34103C Murata Power Solutions	FIXED IND 10UH 800MA 200 MOHM	0
12RS223C Murata Power Solutions	FIXED IND 22UH 3.3A 42 MOHM TH	1614

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