Fixed Inductors

Part Number	Description / PDF	Quantity
ELL-6PG270M Panasonic	FIXED IND 27UH 800MA 260 MOHM	839
ELJ-FA680JFD Panasonic	FIXED IND 68UH 85MA 9 OHM SMD	6
ELL-6RH6R2M Panasonic	FIXED IND 6.2UH 1.4A 62 MOHM SMD	880
ELL-VEG6R8N Panasonic	FIXED IND 6.8UH 650MA 350 MOHM	1926
ELJ-FCR56MF Panasonic	FIXED IND 560NH 150MA 1.1 OHM	1740
ETQ-P4LR19WFC Panasonic	FIXED IND 190NH 28A 0.7 MOHM SMD	2000
ELJ-FA3R9KF Panasonic	FIXED IND 3.9UH 175MA 1.3 OHM	392
ELJ-FA1R8JF Panasonic	FIXED IND 1.8UH 200MA 820 MOHM	1
ELJ-FAR82MF2 Panasonic	FIXED IND 820NH 245MA 610 MOHM	126
ELJ-QE18NGFA Panasonic	FIXED IND 18NH 320MA 410 MOHM	2562
ELC-18E562L Panasonic	FIXED IND 5.6MH 460MA 1.6 OHM TH	0
ELJ-RF43NJFB Panasonic	FIXED IND 43NH 150MA 1.9 OHM SMD	15071
ELJ-NC47NJF Panasonic	FIXED IND 47NH 205MA 590 MOHM	79
ELL-5PR6R8N Panasonic	FIXED IND 6.8UH 1.4A 85 MOHM SMD	1239
ETQ-P3M100KVP Panasonic	FIXED IND 10UH 2.9A 105.6 MOHM	460
ELJ-NCR12KF Panasonic	FIXED IND 120NH 170MA 870 MOHM	2265
ELJ-RF1N0ZFB Panasonic	FIXED IND 1NH 400MA 50 MOHM SMD	689
ELJ-FAR22KF2 Panasonic	FIXED IND 220NH 360MA 290 MOHM	179
ETQ-P4M100KVK Panasonic	FIXED IND 10UH 5.2A 45.76 MOHM	5846
ELL-6PG3R3N Panasonic	FIXED IND 3.3UH 2A 44 MOHM SMD	2691

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