Fixed Inductors

Part Number	Description / PDF	Quantity
ELL-4FG470MA Panasonic	FIXED IND 47UH 330MA 1.6 OHM SMD	2455
ELJ-NC33NJF Panasonic	FIXED IND 33NH 220MA 510 MOHM	1656
ELT-5KN135C Panasonic	FIXED IND 1.5MH 40MA 20 OHM SMD	0
ELJ-RF2N2DFB Panasonic	FIXED IND 2.2NH 400MA 90 MOHM	2775
ELT-5KT6R8MB Panasonic	FIXED IND 6.8UH 760MA 300 MOHM	13056
ELL-SFG221MA Panasonic	FIXED IND 220UH 145MA 6.7 OHM	3973
ELJ-FCR39KF Panasonic	FIXED IND 390NH 160MA 950 MOHM	808
ETQ-P3MR68YFN Panasonic	FIXED IND 680NH 12A 6.9 MOHM SMD	2606
ELJ-SA680KF Panasonic	FIXED IND 68UH 6MA 5 OHM SMD	11
ELL-4GG470M Panasonic	FIXED IND 47UH 350MA 1.25 OHM	940
ELL-8UV100M Panasonic	FIXED IND 10UH 3MA 22 OHM SMD	391
ELJ-FB5R6KF Panasonic	FIXED IND 5.6UH 330MA 880 MOHM	202
ELL-6PG820M Panasonic	FIXED IND 82UH 450MA 800 MOHM	500
ETQ-P4M1R5KVK Panasonic	FIXED IND 1.5UH 15.1A 5.39 MOHM	1062
ETQ-P5M3R3YGC Panasonic	FIXED IND 3.3UH 14.7A 7.81 MOHM	500
ELL-CTV470M Panasonic	FIXED IND 47UH 1.9A 69 MOHM SMD	0
ELL-4FG6R8NA Panasonic	FIXED IND 6.8UH 860MA 220 MOHM	2690
ELC-18E561L Panasonic	FIXED IND 560UH 1.4A 170 MOHM TH	0
ELT-3KN123B Panasonic	FIXED IND 1MH 30MA 25 OHM SMD	3359
ELL-ATV180M Panasonic	FIXED IND 18UH 2.5A 38 MOHM SMD	439

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