Fixed Inductors

Part Number	Description / PDF	Quantity
ELC-18E471L Panasonic	FIXED IND 470UH 1.5A 150 MOHM TH	0
ELL-8UV221M Panasonic	FIXED IND 220UH 0.66MA 370 OHM	3920
ELT-5KT470LB Panasonic	FIXED IND 47UH 300MA 1.7 OHM SMD	4506
ETQ-P3M150KVN Panasonic	FIXED IND 15UH 3A 109.12 MOHM	2690
ELJ-PE15NKFA Panasonic	FIXED IND 15NH 900MA 100 MOHM	0
ELT-5KT470LA Panasonic	FIXED IND 47UH 300MA 1.7 OHM SMD	4188
ELJ-QF10NGF Panasonic	FIXED IND 10NH 320MA 410 MOHM	1400
ETQ-P4M6R8KVC Panasonic	FIXED IND 6.8UH 8.9A 20.35 MOHM	0
ETQ-P4M470YFN Panasonic	FIXED IND 47UH 2.2A 231 MOHM SMD	2026
ELJ-QE15NGFA Panasonic	FIXED IND 15NH 350MA 340 MOHM	5281
ELJ-PF5N6DFB Panasonic	FIXED IND 5.6NH 1.2A 120 MOHM	18708
ETQ-P3WR47WFN Panasonic	FIXED IND 470NH 20A 4.2 MOHM SMD	9358
ELL-6GG4R7M Panasonic	FIXED IND 4.7UH 1.55A 70 MOHM	1042
ELJ-FC1R2KF Panasonic	FIXED IND 1.2UH 180MA 750 MOHM	1753
ELT-5KT150LA Panasonic	FIXED IND 15UH 510MA 580 MOHM	4020
ELJ-QE10NGFA Panasonic	FIXED IND 10NH 450MA 210 MOHM	1216
ELC-16B560L Panasonic	FIXED IND 56UH 3.4A 51 MOHM TH	185
ELJ-RE1N2DFA Panasonic	FIXED IND 1.2NH 500MA 60 MOHM	223
ELJ-NAR12MF Panasonic	FIXED IND 120NH 240MA 670 MOHM	6755
ELG-TEAR47NA Panasonic	FIXED IND 470NH 1.2A 100 MOHM	851

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