Fixed Inductors

Part Number	Description / PDF	Quantity
ELC-18E471 Panasonic	FIXED IND 470UH 1.5A 150 MOHM TH	0
ELL-6GG3R9M Panasonic	FIXED IND 3.9UH 1.7A 60 MOHM SMD	45
ELT-5KT220LB Panasonic	FIXED IND 22UH 420MA 900 MOHM	9645
ELJ-PE22NKFA Panasonic	FIXED IND 22NH 700MA 150 MOHM	17
ETQ-P5M101YGC Panasonic	FIXED IND 97UH 2.7A 229 MOHM SMD	278
ELL-4FG1R5NA Panasonic	FIXED IND 1.5UH 1.7A 60 MOHM SMD	3710
ELL-4LG330MA Panasonic	FIXED IND 33UH 510MA 610 MOHM	4832
ELJ-RE1N0DFA Panasonic	FIXED IND 1NH 500MA 50 MOHM SMD	65153
ETQ-P3M6R8KVP Panasonic	FIXED IND 6.8UH 3.5A 72.27 MOHM	0
ELL-SFG1R0NA Panasonic	FIXED IND 1UH 1.7A 49 MOHM SMD	3990
ELC-18E682 Panasonic	FIXED IND 6.8MH 390MA 2.2 OHM TH	0
ETQ-P5M2R5YFK Panasonic	FIXED IND 2.5UH 14A 8.4 MOHM SMD	340
ELL-5GM470M Panasonic	FIXED IND 47UH 390MA 930 MOHM	1995
ELJ-FB391JF Panasonic	FIXED IND 390UH 70MA 19 OHM SMD	71783
ETQ-P4M220YFP Panasonic	FIXED IND 22UH 2.3A 179 MOHM SMD	0
ELL-CTV561M Panasonic	FIXED IND 560UH 540MA 810 MOHM	343
ETQ-P5M2R0YLC Panasonic	FIXED IND 2UH 19.4A 5.06 MOHM	367
ELG-TEA4R7NA Panasonic	FIXED IND 4.7UH 800MA 300 MOHM	1
ETQ-P6F6R4HFA Panasonic	FIXED IND 6.4UH 7.9A 8.64 MOHM	5633
ELL-8UV470M Panasonic	FIXED IND 47UH 1.25MA 100 OHM	1331

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