Fixed Inductors

Part Number	Description / PDF	Quantity
ETQ-P8M2R5JFA Panasonic	FIXED IND 2.5UH 23A 2.86 MOHM	137
ELC-18E152 Panasonic	FIXED IND 1.5MH 900MA 510 MOHM	0
ELJ-FB271JF Panasonic	FIXED IND 270UH 80MA 14 OHM SMD	5
ELL-SFG471MA Panasonic	FIXED IND 470UH 110MA 12.3 OHM	1996
ELJ-RF22NJF Panasonic	FIXED IND 22NH 200MA 800 MOHM	417
ELL-CTV121M Panasonic	FIXED IND 120UH 1.1A 190 MOHM	3274
ELC-18E331 Panasonic	FIXED IND 330UH 1.9A 110 MOHM TH	0
ELC-18E103 Panasonic	FIXED IND 10MH 330MA 2.7 OHM TH	0
ELC-3FN150M Panasonic	FIXED IND 15UH 370MA 1 OHM SMD	3707
ELC-18E682L Panasonic	FIXED IND 6.8MH 390MA 2.2 OHM TH	0
ELJ-RF3N6ZFB Panasonic	FIXED IND 3.6NH 380MA 140 MOHM	16257
ELL-VEG1R0N Panasonic	FIXED IND 1UH 1.6A 61 MOHM SMD	740
ELC-18E181 Panasonic	FIXED IND 180UH 2.5A 67 MOHM TH	0
ELJ-RE68NJFA Panasonic	FIXED IND 68NH 250MA 1.3 OHM SMD	1
ELL-6GG1R0N Panasonic	FIXED IND 1UH 2.5A 27 MOHM SMD	5
ELJ-FAR22MF2 Panasonic	FIXED IND 220NH 360MA 290 MOHM	6217
ELJ-RF1N0DFB Panasonic	FIXED IND 1NH 400MA 50 MOHM SMD	41140
ELT-5KT150LB Panasonic	FIXED IND 15UH 510MA 580 MOHM	12909
ELL-8UV101M Panasonic	FIXED IND 100UH 0.82MA 160 OHM	714
ELJ-FCR39MF Panasonic	FIXED IND 390NH 160MA 950 MOHM	1162

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