Fixed Inductors

Part Number	Description / PDF	Quantity
MDH12577C-4R7NA=P3 TOKO / Murata	FIXED IND 4.7UH 5.4A 9MOHM SMD	193
LQG15HZ82NH02D TOKO / Murata	FIXED IND 82NH 200MA 1.2 OHM SMD	5944
LQH32PH1R0NN0L TOKO / Murata	FIXED IND 1UH 2.05A 54 MOHM SMD	357
LQW18AN68NG8ZD TOKO / Murata	FIXED IND 68NH 630MA 380 MOHM	686
LQW2BAS12NG00L TOKO / Murata	FIXED IND 12NH 600MA 150 MOHM	2016
LQM2HPN2R2MJHL TOKO / Murata	FIXED IND 2.2UH 1.5A 138 MOHM	138
LQW15AWR22G80D TOKO / Murata	FIXED IND 220NH 220MA 2.75 OHM	0
LQP02HQ5N1H02L TOKO / Murata	FIXED IND 5.1NH 350MA 350 MOHM	0
LQP03TN39NH02D TOKO / Murata	FIXED IND 39NH 120MA 3 OHM SMD	16833
LQW15AN1N6D80D TOKO / Murata	FIXED IND 1.6NH 1.45A 45 MOHM	0
LQH43NN101K03L TOKO / Murata	FIXED IND 100UH 160MA 2.5 OHM	0
LQH3NPZ220MMEL TOKO / Murata	FIXED IND 22UH 540MA 480 MOHM	815
LQW15AN12NJ80D TOKO / Murata	FIXED IND 12NH 1.24A 93 MOHM SMD	0
LQP02HQ2N0C02L TOKO / Murata	FIXED IND 2NH 700MA 100 MOHM SMD	0
LQG15HN7N5H02D TOKO / Murata	FIXED IND 7.5NH 500MA 240 MOHM	9510
LQP03TQ7N5J02D TOKO / Murata	FIXED IND 7.5NH 300MA 550 MOHM	19866
LQP03HQ5N1H02D TOKO / Murata	FIXED IND 5.1NH 400MA 250 MOHM	11361
LQG15WZ43NH02D TOKO / Murata	FIXED IND 43NH 190MA 1.6 OHM SMD	0
LQW15AN22NJ0ZD TOKO / Murata	FIXED IND 22NH 310MA 300MOHM SMD	0
LQM18DH6R8M70L TOKO / Murata	FIXED IND 6.8UH 330MA 960 MOHM	3370

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