Fixed Inductors

Part Number	Description / PDF	Quantity
ELC-18E222L Panasonic	FIXED IND 2.2MH 730MA 630 MOHM	0
ELC-3GN330M Panasonic	FIXED IND 33UH 280MA 1.4 OHM SMD	5817
ELJ-NAR15MF Panasonic	FIXED IND 150NH 230MA 720 MOHM	4959
ETQ-P3W3R3WFN Panasonic	FIXED IND 3.3UH 7.4A 28.8 MOHM	0
ELJ-PE18NKFA Panasonic	FIXED IND 18NH 800MA 120 MOHM	42
ELJ-FAR39MF2 Panasonic	FIXED IND 390NH 305MA 390 MOHM	1592
ELL-6PM270M Panasonic	FIXED IND 27UH 620MA 220 MOHM	799
ELL-8TP471MB Panasonic	FIXED IND 470UH 480MA 1 OHM SMD	789
ELJ-RF2N2ZFB Panasonic	FIXED IND 2.2NH 400MA 90 MOHM	3545
ELL-CTV270M Panasonic	FIXED IND 27UH 2.3A 43 MOHM SMD	0
ETQ-P3W2R2WFN Panasonic	FIXED IND 2.2UH 9A 17.8 MOHM SMD	0
ELC-18E221L Panasonic	FIXED IND 220UH 2.1A 76 MOHM TH	0
ELL-ATV680M Panasonic	FIXED IND 68UH 1.2A 130 MOHM SMD	489
ELL-6GG6R8M Panasonic	FIXED IND 6.8UH 1.3A 110 MOHM	1697
ELJ-SC390KF Panasonic	FIXED IND 39UH 13MA 5.7 OHM SMD	1383
ETQ-P3M2R2KVN Panasonic	FIXED IND 2.2UH 7.9A 15.95 MOHM	0
ELL-4LG1R5NA Panasonic	FIXED IND 1.5UH 1.8A 48 MOHM SMD	2836
ELC-18E562 Panasonic	FIXED IND 5.6MH 460MA 1.6 OHM TH	0
ELJ-RF2N7ZFB Panasonic	FIXED IND 2.7NH 400MA 100 MOHM	4115
ELL-8UV2R0N Panasonic	FIXED IND 2UH 5.1MA 8.7 OHM SMD	959

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