Fixed Inductors

Image	Part Number	Description / PDF	Quantity	Rfq
	ELJ-RE39NGFA Panasonic	FIXED IND 39NH 300MA 800 MOHM	0
	ELC-15E221 Panasonic	FIXED IND 220UH 2A 140 MOHM TH	0
	ELL-ATV4R3N Panasonic	FIXED IND 4.3UH 5A 10 MOHM SMD	0
	ELC-15E180 Panasonic	FIXED IND 18UH 4.5A 24 MOHM TH	0
	ELC-15E272 Panasonic	FIXED IND 2.7MH 600MA 1.4 OHM TH	0
	ELL-CTV820M Panasonic	FIXED IND 82UH 1.4A 120 MOHM SMD	0
	ELL-5GM3R6N Panasonic	FIXED IND 3.6UH 1.3A 70 MOHM SMD	0
	ELC-18B270L Panasonic	FIXED IND 27UH 4.8A 28 MOHM TH	0
	ELL-4GG101M Panasonic	FIXED IND 100UH 250MA 2.4 OHM	0
	ELJ-PE22NKF Panasonic	FIXED IND 22NH 700MA 150 MOHM	0
	ELC-12E181L Panasonic	FIXED IND 180UH 1A 200 MOHM TH	0
	ELJ-PC220KF Panasonic	FIXED IND 22UH 160MA 4 OHM SMD	0
	ELL-SFG1R2NA Panasonic	FIXED IND 1.2UH 1.55A 58 MOHM	0
	ELL-ATP471MB Panasonic	FIXED IND 470UH 500MA 780MOHM SM	0
	ELC-10D220E Panasonic	FIXED IND 22UH 3.2A 40 MOHM TH	0
	ELJ-ND15NJF Panasonic	FIXED IND 15NH 520MA 240 MOHM	0
	ELJ-PA100KF2 Panasonic	FIXED IND 10UH 590MA 350 MOHM	0
	ELL-ATV470M Panasonic	FIXED IND 47UH 1.55A 94 MOHM SMD	0
	ETQ-P6F1R1BFA Panasonic	FIXED IND 1.06UH 16A 2.24 MOHM	0
	ELC-10E271L Panasonic	FIXED IND 270UH 540MA 590 MOHM	0

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