Fixed Inductors

Part Number	Description / PDF	Quantity
ELL-6PV9R1N Panasonic	FIXED IND 9.1UH 1.1A 76 MOHM SMD	831
ELL-6PG3R9N Panasonic	FIXED IND 3.9UH 1.9A 51 MOHM SMD	1443
ELL-6PG6R8N Panasonic	FIXED IND 6.8UH 1.6A 70 MOHM SMD	9
ELC-18E101L Panasonic	FIXED IND 100UH 3A 44 MOHM TH	0
ELL-6UH820M Panasonic	FIXED IND 82UH 650MA 260 MOHM	45
ELJ-NC12NKF Panasonic	FIXED IND 12NH 270MA 340 MOHM	3
ELC-18E5R6 Panasonic	FIXED IND 5.6UH 6.7A 11 MOHM TH	0
ELL-8TP3R3NB Panasonic	FIXED IND 3.3UH 4.2A 13 MOHM SMD	24
ELL-6GM120M Panasonic	FIXED IND 12UH 830MA 170 MOHM	323
ETQ-P4M1R0KVC Panasonic	FIXED IND 1UH 23.9A 2.86 MOHM	0
ELC-3FN2R7N Panasonic	FIXED IND 2.7UH 950MA 150 MOHM	5481
ELL-6SH121M Panasonic	FIXED IND 120UH 370MA 750 MOHM	133
ELL-8TP181MB Panasonic	FIXED IND 180UH SMD	985
ELJ-FCR22MF Panasonic	FIXED IND 220NH 190MA 700 MOHM	149
ELJ-PF2N7DFB Panasonic	FIXED IND 2.7NH 1.8A 50 MOHM SMD	90
ELJ-QE2N2ZFA Panasonic	FIXED IND 2.2NH 970MA 40 MOHM	11
ELJ-FB331JF Panasonic	FIXED IND 330UH 75MA 16 OHM SMD	66894
ELC-3GN2R2N Panasonic	FIXED IND 2.2UH 1A 100 MOHM SMD	1262
ETQ-P8M1R0JFA Panasonic	FIXED IND 1UH 31.8A 1.5 MOHM SMD	0
ELJ-FC120KF Panasonic	FIXED IND 12UH 75MA 4.1 OHM SMD	1777

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