Fixed Inductors

Part Number	Description / PDF	Quantity
LQH2MPZR47NGRL TOKO / Murata	FIXED IND 470NH 1.06A 216 MOHM	5556
LQW18AN8N2G80D TOKO / Murata	FIXED IND 8.2NH 1.6A 52 MOHM SMD	21252
LQH31HNR50K03L TOKO / Murata	FIXED IND 500NH 260MA 572 MOHM	1966
B1047AS-6R8N=P3 TOKO / Murata	FIXED IND 6.8UH 3.4A 36 MOHM SMD	300
LQW15AN2N2B8ZD TOKO / Murata	FIXED IND 2.2NH 2.53A 22 MOHM	6000
LQW18AN43NG00D TOKO / Murata	FIXED IND 43NH 380MA 290 MOHM	0
LQW18CA85NJ00D TOKO / Murata	FIXED IND 85NH 1.65A 48 MOHM SMD	3510
LQG15HZ6N2C02D TOKO / Murata	FIXED IND 6.2NH 600MA 200 MOHM	0
LQW03AW3N1C00D TOKO / Murata	FIXED IND 3.1NH 720MA 70 MOHM	0
LQP02TN4N0B02D TOKO / Murata	FIXED IND 4NH 180MA 1.3 OHM SMD	0
LQM2HPN1R0MJ0L TOKO / Murata	FIXED IND 1UH 1.5A 113 MOHM SMD	30783
LQP03TG18NJ02D TOKO / Murata	FIXED IND 18NH 160MA 2.28 OHM	0
LQW18AN6N8G8ZD TOKO / Murata	FIXED IND 6.8NH 1.9A 40 MOHM	3280
LQW18AS3N9G00D TOKO / Murata	FIXED IND 3.9NH 700MA 80MOHM SMD	0
LQP02HQ3N8B02E TOKO / Murata	FIXED IND 3.8NH 350MA 350 MOHM	0
LQW18ANR25G8ZD TOKO / Murata	FIXED IND 250NH 250MA 2.28 OHM	4885
LQP03TG0N5B02D TOKO / Murata	FIXED IND 0.5NH 850MA 80 MOHM	34980
LQP03TG1N8C02D TOKO / Murata	FIXED IND 1.8NH 500MA 200 MOHM	0
LQW15AN15NJ80D TOKO / Murata	FIXED IND 15NH 1.15A 114 MOHM	0
FDSD0412-H-4R7M=P3 TOKO / Murata	FIXED IND 4.7UH 1.9A 161 MOHM	3152

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