Fixed Inductors

Part Number	Description / PDF	Quantity
LQP02HQ4N1C02L TOKO / Murata	FIXED IND 4.1NH 350MA 350 MOHM	0
DFEH12060D-4R7M=P3 TOKO / Murata	FIXED IND 4.7UH 10A 11 MOHM SMD	313
DFE322512F-2R2M=P2 TOKO / Murata	FIXED IND 2.2UH 2.6A 66MOHM SMD	0
LQP03TN18NH02D TOKO / Murata	FIXED IND 18NH 200MA 800 MOHM	32301
LQW15CAR50K00D TOKO / Murata	FIXED IND 500NH 270MA 970 MOHM	8704
LQP02TN1N3B02D TOKO / Murata	FIXED IND 1.3NH 220MA 600 MOHM	0
LQH32NZ471J23L TOKO / Murata	FIXED IND 470UH 45MA 25 OHM SMD	1638
LQW18CN15NJ00D TOKO / Murata	FIXED IND 15NH 2.2A 25 MOHM SMD	3665
LQW15AN4N2D8ZD TOKO / Murata	FIXED IND 4.2NH 1.8A 44 MOHM	8813
FDSD0630-H-1R0MB=P3 TOKO / Murata	FIXED IND 1UH 9.4A 11 MOHM SMD	1000
LQP15MN3N0B02D TOKO / Murata	FIXED IND 3NH 190MA 400 MOHM SMD	3
LQP02TN24NJ02D TOKO / Murata	FIXED IND 24NH 120MA 5.5 OHM SMD	0
1225AS-H-1R0N=P2 TOKO / Murata	FIXED IND 1UH 2.7A 43 MOHM SMD	1899
LQW15AN1N5D8ZD TOKO / Murata	FIXED IND 1.5NH 2.1A 28 MOHM	2784
LQW04AN12NJ00D TOKO / Murata	FIXED IND 12NH 310MA 280 MOHM	0
LQP02HQ5N6J02E TOKO / Murata	FIXED IND 5.6NH 300MA 400 MOHM	0
LQG18HN12NJ00D TOKO / Murata	FIXED IND 12NH 600MA 350 MOHM	12938
LQW15AN5N6G8ZD TOKO / Murata	FIXED IND 5.6NH 1.77A 40 MOHM	9751
LQW18AS15NG0CD TOKO / Murata	FIXED IND 15NH 700MA 170 MOHM	3847
LQP03TN91NH02D TOKO / Murata	FIXED IND 91NH 80MA 10 OHM SMD	8081

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