Fixed Inductors

Part Number	Description / PDF	Quantity
ELJ-RF3N9ZFB Panasonic	FIXED IND 3.9NH 360MA 150 MOHM	280
ELJ-NC39NKF Panasonic	FIXED IND 39NH 215MA 550 MOHM	3153
ELL-6RH390M Panasonic	FIXED IND 39UH 550MA 410 MOHM	303
ELL-8UV330M Panasonic	FIXED IND 33UH 1.65MA 78 OHM SMD	960
ETQ-P3M2R2YFP Panasonic	FIXED IND 2.2UH 5.8A 24.8 MOHM	1242
ELJ-PF2N2DFB Panasonic	FIXED IND 2.2NH 1.9A 40 MOHM SMD	42697
ELL-6PM9R1N Panasonic	FIXED IND 9.1UH 1.2A 77 MOHM SMD	469
ETQ-P4LR42AFM Panasonic	FIXED IND 420NH 17A 1.5 MOHM SMD	2998
ELC-18E150 Panasonic	FIXED IND 15UH 5.4A 17 MOHM TH	0
ELC-3GN220M Panasonic	FIXED IND 22UH 330MA 950 MOHM	8928
ETQ-P4MR68KVK Panasonic	FIXED IND 680NH 19.6A 3.19 MOHM	255
ELC-18E681L Panasonic	FIXED IND 680UH 1.2A 190 MOHM TH	0
ELJ-FA330KF Panasonic	FIXED IND 33UH 85MA 5.6 OHM SMD	24
ELC-18E6R8L Panasonic	FIXED IND 6.8UH 6.5A 13 MOHM TH	0
ELJ-PE2N2KF Panasonic	FIXED IND 2.2NH 2.1A 30 MOHM SMD	3750
ETQ-P4M6R8YFN Panasonic	FIXED IND 6.8UH 5.2A 43.2 MOHM	0
ELJ-RF1N5DFB Panasonic	FIXED IND 1.5NH 400MA 70 MOHM	6164
ETQ-P4M100YFN Panasonic	FIXED IND 10UH 4.5A 59.6 MOHM	4007
ELJ-PE15NKF Panasonic	FIXED IND 15NH 900MA 100 MOHM	2965
ELL-VEG1R5N Panasonic	FIXED IND 1.5UH 1.4A 74 MOHM SMD	3639

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