Fixed Inductors

Part Number	Description / PDF	Quantity
ETQ-P1W2R2WFP Panasonic	FIXED IND 2.2UH 3.4A 77.3 MOHM	2407
ELL-6GG101M Panasonic	FIXED IND 100UH 350MA 1.48 OHM	0
ELL-VEG4R7N Panasonic	FIXED IND 4.7UH 770MA 240 MOHM	12872
ELJ-FA820JFD Panasonic	FIXED IND 82UH 75MA 12 OHM SMD	2969
ELJ-QE3N9ZFA Panasonic	FIXED IND 3.9NH 750MA 70 MOHM	28143
ETQ-P3M100KVN Panasonic	FIXED IND 10UH 3.6A 78.1 MOHM	0
ELJ-PA271KF Panasonic	FIXED IND 270UH 55MA 14.5 OHM	76
ELJ-RF39NGFB Panasonic	FIXED IND 39NH 150MA 1.7 OHM SMD	5073
ELL-CTV5R6N Panasonic	FIXED IND 5.6UH 4.9A 11 MOHM SMD	117
ELL-4LG150MA Panasonic	FIXED IND 15UH 730MA 300 MOHM	37
ETQ-P5M2R5YSK Panasonic	FIXED IND 2.45UH 14.1A 8.14MOHM	734
ELL-CTV331M Panasonic	FIXED IND 330UH 660MA 500 MOHM	240
ELL-5PR1R0N Panasonic	FIXED IND 1UH 3A 21 MOHM SMD	1153
ETQ-P3M4R7KVN Panasonic	FIXED IND 4.7UH 5.6A 31.9 MOHM	0
ELL-6SH181M Panasonic	FIXED IND 180UH 300MA 1.3 OHM	1266
ELL-6PG470M Panasonic	FIXED IND 47UH 600MA 470 MOHM	0
ELJ-PF3N9DF Panasonic	FIXED IND 3.9NH 1.4A 80 MOHM SMD	5220
ELT-3KN163B Panasonic	FIXED IND 1.1MH 30MA 32 OHM SMD	2694
ETQ-P6F1R3LFA Panasonic	FIXED IND 1.3UH 12.5A 3.3 MOHM	0
ELJ-FB3R9KF Panasonic	FIXED IND 3.9UH 360MA 740 MOHM	2

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