Fixed Inductors

Part Number	Description / PDF	Quantity
LQP02HQ7N5H02E TOKO / Murata	FIXED IND 7.5NH 300MA 500 MOHM	0
LQH66SN331M03L TOKO / Murata	FIXED IND 330UH 280MA 2.52 OHM	133
LQP02HQ3N9B02E TOKO / Murata	FIXED IND 3.9NH 350MA 350 MOHM	0
LQW15AN8N9J80D TOKO / Murata	FIXED IND 8.9NH 1.42A 70 MOHM	0
LQH32DN470K23L TOKO / Murata	FIXED IND 47UH 170MA 1.69 OHM	0
LQH43NN821K03L TOKO / Murata	FIXED IND 820UH 60MA 20.5 OHM	0
LQW15AN9N9G8ZD TOKO / Murata	FIXED IND 9.9NH 1.4A 81 MOHM	8459
DFEH7030D-6R8M=P3 TOKO / Murata	FIXED IND 6.8UH 3.5A 59 MOHM	352
LQW18AN56NG80D TOKO / Murata	FIXED IND 56NH 770MA 260 MOHM	3064
DFEH10040D-100M=P3 TOKO / Murata	FIXED IND 10UH 5.7A 33 MOHM SMD	331
LQH43MN270K03L TOKO / Murata	FIXED IND 27UH 300MA 1.1 OHM SMD	266
LQH2HPZ1R0MDRL TOKO / Murata	FIXED IND 1UH 960MA 288 MOHM SMD	0
LQH43NN5R6M03L TOKO / Murata	FIXED IND 5.6UH 500MA 470 MOHM	0
LQP03TN3N5C02D TOKO / Murata	FIXED IND 3.5NH 450MA 250 MOHM	0
LQG15WZ3N9S02D TOKO / Murata	FIXED IND 3.9NH 900MA 90 MOHM	9114
LQH32CH100K23L TOKO / Murata	FIXED IND 10UH 300MA 440 MOHM	0
LQW15AN4N4B8ZD TOKO / Murata	FIXED IND 4.4NH 1.6A 52 MOHM	4035
LQW18AN2N4C8ZD TOKO / Murata	FIXED IND 2.4NH 2.4A 26 MOHM	2208
LQM2MPNR47MGHL TOKO / Murata	FIXED IND 470NH 2.5A 46 MOHM SMD	0
DFE201612PD-R15M=P2 TOKO / Murata	FIXED IND 150NH 5.2A 18MOHM SMD	269

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