Fixed Inductors

Part Number	Description / PDF	Quantity
LQW18AN43NG8ZD TOKO / Murata	FIXED IND 43NH 840MA 210 MOHM	734
LQP03TG68NJ02D TOKO / Murata	FIXED IND 68NH 90MA 6.25 OHM SMD	1499
LQW18AN9N5C80D TOKO / Murata	FIXED IND 9.5NH 1.6A 52 MOHM SMD	0
LQW18ANR27G0ZD TOKO / Murata	FIXED IND 270NH 110MA 3.4 OHM	1319
LQW15AN36NJ8ZD TOKO / Murata	FIXED IND 36NH 540MA 431 MOHM	3115
LQG15WH36NH02D TOKO / Murata	FIXED IND 36NH 190MA 1.5 OHM SMD	0
LQG15WZ30NJ02D TOKO / Murata	FIXED IND 30NH 220MA 1.3 OHM SMD	9513
LQG18HHR10J00D TOKO / Murata	FIXED IND 100NH 300MA 900 MOHM	5111
LQH5BPN1R0N38L TOKO / Murata	FIXED IND 1UH 4.6A 12 MOHM SMD	330
LQW18AN31NG8ZD TOKO / Murata	FIXED IND 31NH 1.1A 110 MOHM	6972
LQW15AN8N4G8ZD TOKO / Murata	FIXED IND 8.4NH 1.5A 69 MOHM	7313
MDH12577C-150MA=P3 TOKO / Murata	FIXED IND 15UH 3.6A 22MOHM SMD	300
LQH32NH181J23L TOKO / Murata	FIXED IND 180UH 60MA 9.12 OHM	1485
LQH3NPH1R0MMEL TOKO / Murata	FIXED IND 1.0UH 3000MA POWRTRNAU	0
LQW15AWR22J80D TOKO / Murata	FIXED IND 220NH 220MA 2.75 OHM	489
LQP02TN20NH02D TOKO / Murata	FIXED IND 20NH 100MA 5 OHM SMD	0
LQH43CN330K03L TOKO / Murata	FIXED IND 33UH 310MA 1 OHM SMD	5819
LQG15HZ18NH02D TOKO / Murata	FIXED IND 18NH 400MA 360 MOHM	944
LQH2HPZR47NJRL TOKO / Murata	FIXED IND 470NH 2.75A 37.2 MOHM	8738
LQW15AN8N7G00D TOKO / Murata	FIXED IND 8.7NH 540MA 140 MOHM	9596

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