Fixed Inductors

Part Number	Description / PDF	Quantity
LQP03HQ4N3H02D TOKO / Murata	FIXED IND 4.3NH 500MA 170 MOHM	3870
LQW18ANR22J80D TOKO / Murata	FIXED IND 220NH 280MA 2.08 OHM	291
LQP02TN12NH02D TOKO / Murata	FIXED IND 12NH 140MA 2.8 OHM SMD	0
LQW15AN3N9C80D TOKO / Murata	FIXED IND 3.9NH 1.95A 30 MOHM	0
LQW18ASR22J0ZD TOKO / Murata	FIXED IND 220NH 200MA 2.1 OHM	2600
LQG15WZ2N5B02D TOKO / Murata	FIXED IND 2.5NH 900MA 70 MOHM	0
LQW18ANR39J8ZD TOKO / Murata	FIXED IND 390NH 190MA 4.23 OHM	4000
LQP02TN1N6B02D TOKO / Murata	FIXED IND 1.6NH 220MA 600 MOHM	0
LQP02TN2N5B02D TOKO / Murata	FIXED IND 2.5NH 200MA 800 MOHM	0
LQH2MCN1R5M02L TOKO / Murata	FIXED IND 1.5UH 445MA 520 MOHM	0
LQP02HQ2N0B02L TOKO / Murata	FIXED IND 2NH 700MA 100 MOHM SMD	0
LQH3NPZ3R3MGRL TOKO / Murata	FIXED IND 3.3UH 940MA 144 MOHM	2277
LQG15HS1N1C02D TOKO / Murata	FIXED IND 1.1NH 1A 70 MOHM SMD	9670
LQW2UASR27G0CL TOKO / Murata	FIXED IND 270NH 500MA 910 MOHM	1370
LQW15AN3N8C8ZD TOKO / Murata	FIXED IND 3.8NH 1.95A 30 MOHM	9432
LQW15AN4N2B80D TOKO / Murata	FIXED IND 4.2NH 1.8A 44 MOHM SMD	0
1231AS-H-1R2N=P3 TOKO / Murata	FIXED IND 1.2UH 2.9A 36 MOHM SMD	1849
LQP02HQ6N2H02E TOKO / Murata	FIXED IND 6.2NH 300MA 400 MOHM	0
LQW03AW5N6C00D TOKO / Murata	FIXED IND 5.6NH 330MA 330 MOHM	0
LQP03TQ1N9C02D TOKO / Murata	FIXED IND 1.9NH 650MA 100 MOHM	11363

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