Fixed Inductors

Part Number	Description / PDF	Quantity
LQH31MN120J03L TOKO / Murata	FIXED IND 12UH 95MA 2.7 OHM SMD	0
LQG15WH3N3S02D TOKO / Murata	FIXED IND 3.3NH 900MA 80 MOHM	8870
LQH31MN2R2J03L TOKO / Murata	FIXED IND 2.2UH 140MA 700 MOHM	392
LQW15CA22NJ00D TOKO / Murata	FIXED IND 22NH 1.3A 60 MOHM SMD	3443
LQH31HNR75K03L TOKO / Murata	FIXED IND 750NH 190MA 1.027 OHM	0
LQW04AN11NH00D TOKO / Murata	FIXED IND 11NH 310MA 280 MOHM	0
LQW15AN5N7B80D TOKO / Murata	FIXED IND 5.7NH 1.77A 40 MOHM	0
DD1217AS-H-330M=P3 TOKO / Murata	FIXED IND 33UH 2.2A 132 MOHM	171
LQM18PN1R5MFRL TOKO / Murata	FIXED IND 1.5UH 800MA 288 MOHM	3249
LQH32PB100MN0L TOKO / Murata	FIXED IND 10UH 700MA 456 MOHM	0
LQG15WH47NH02D TOKO / Murata	FIXED IND 47NH 190MA 1.6 OHM SMD	0
LQG18HN22NJ00D TOKO / Murata	FIXED IND 22NH 300MA 500 MOHM	7274
LQW15AN53NJ80D TOKO / Murata	FIXED IND 53NH 415MA 696 MOHM	0
LQH43NN471J03L TOKO / Murata	FIXED IND 470UH 80MA 11.8 OHM	0
LQW15AN5N9B8ZD TOKO / Murata	FIXED IND 5.9NH 1.77A 40 MOHM	9414
1276AS-H-3R3M=P2 TOKO / Murata	FIXED IND 3.3UH 1.4A 190 MOHM	3136
LQP02HQ10NH02L TOKO / Murata	FIXED IND 10NH 300MA 600 MOHM	0
LQG15WH3N3C02D TOKO / Murata	FIXED IND 3.3NH 900MA 80 MOHM	8134
LQH32CNR15M33L TOKO / Murata	FIXED IND 150NH 1.45A 36.4 MOHM	3184
LQG15WH47NJ02D TOKO / Murata	FIXED IND 47NH 190MA 1.6 OHM SMD	6346

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