Fixed Inductors

Part Number	Description / PDF	Quantity
#B953AS-471M=P3 TOKO / Murata	FIXED IND 470UH 700MA 705 MOHM	218
LQW2UASR33J00L TOKO / Murata	FIXED IND 330NH 450MA 1.05 OHM	8645
LQW2UAS33NF00L TOKO / Murata	FIXED IND 33NH 1A 140 MOHM SMD	507
DFE201612PD-R33M=P2 TOKO / Murata	FIXED IND 330NH 3.8A 26MOHM SMD	2887
LQW18CNR65J00D TOKO / Murata	FIXED IND 650NH 430MA 520 MOHM	5327
LQG15HH68NG02D TOKO / Murata	FIXED INDUCTOR	0
LQW2UASR82J00L TOKO / Murata	FIXED IND 820NH 400MA 1.61 OHM	1986
LQH2MCN180M52L TOKO / Murata	FIXED IND 18UH 140MA 5.2 OHM SMD	0
LQP02HQ0N5W02L TOKO / Murata	FIXED IND 0.5NH 1A 40MOHM SMD	0
LQP03TQ1N2W02D TOKO / Murata	FIXED IND 1.2NH 800MA 80 MOHM	5050
LQH43NN100K03L TOKO / Murata	FIXED IND 10UH 400MA 560 MOHM	0
LQW15AN1N5D80D TOKO / Murata	FIXED IND 1.5NH 2.1A 28 MOHM SMD	1513
LQW18AN10NG80D TOKO / Murata	FIXED IND 10NH 1.6A 52 MOHM SMD	2510
LQG15HZ5N1C02D TOKO / Murata	FIXED IND 5.1NH 650MA 180 MOHM	0
LQW18AS68NJ0CD TOKO / Murata	FIXED IND 68NH 600MA 340 MOHM	0
LQM2HPN1R0MJHL TOKO / Murata	FIXED IND 1UH 2.3A 63 MOHM SMD	9727
LQP02TN22NH02D TOKO / Murata	FIXED IND 22NH 120MA 5 OHM SMD	0
LQM18PHR22MFRL TOKO / Murata	FIXED IND 220NH 1.25A 138 MOHM	2906
LQP03TNR10H02D TOKO / Murata	FIXED IND 100NH 80MA 10 OHM SMD	6401
LQM18PN3R3MGHD TOKO / Murata	FIXED IND 3.3UH 1.05A 250 MOHM	583

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