Fixed Inductors

Part Number	Description / PDF	Quantity
ETQ-P8M1R5JFA Panasonic	FIXED IND 1.5UH 27.7A 1.98 MOHM	291
ELJ-FAR47KF2 Panasonic	FIXED IND 470NH 290MA 440 MOHM	3
ELL-5PR100M Panasonic	FIXED IND 10UH 1.06A 150 MOHM	215
ELJ-QF6N8JF Panasonic	FIXED IND 6.8NH 320MA 300 MOHM	137
ELJ-QE2N2DFA Panasonic	FIXED IND 2.2NH 970MA 40 MOHM	4786
ELC-3FN330M Panasonic	FIXED IND 33UH 260MA 1.9 OHM SMD	11014
ELL-VGG220M Panasonic	FIXED IND 22UH 460MA 800 MOHM	405
ETQ-P4M150KVC Panasonic	FIXED IND 15UH 6.3A 40.7 MOHM	12
ELL-6UH681M Panasonic	FIXED IND 680UH 240MA 2.83 OHM	15
ELL-4GG150M Panasonic	FIXED IND 15UH 580MA 500 MOHM	298
ELL-8UV2R7N Panasonic	FIXED IND 2.7UH 4.75MA 10 OHM	371
ELJ-PE3N9KFA Panasonic	FIXED IND 3.9NH 2.1A 40 MOHM SMD	2309
ELJ-FB820JF Panasonic	FIXED IND 82UH 110MA 5.9 OHM SMD	5176
ELC-18E472L Panasonic	FIXED IND 4.7MH 480MA 1.4 OHM TH	0
ELC-3GN3R3N Panasonic	FIXED IND 3.3UH 970MA 130 MOHM	3076
ELL-6GM680M Panasonic	FIXED IND 68UH 350MA 820 MOHM	785
ELL-8UV270M Panasonic	FIXED IND 27UH 1.8MA 53 OHM SMD	985
ETQ-P4M4R7KVC Panasonic	FIXED IND 4.7UH 11.2A 12.98 MOHM	645
ELC-18E122L Panasonic	FIXED IND 1.2MH 950MA 360 MOHM	0
ELJ-PF6N8JF Panasonic	FIXED IND 6.8NH 1.1A 160 MOHM	4153

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