Fixed Inductors

Part Number	Description / PDF	Quantity
ELJ-QF2N7DF Panasonic	FIXED IND 2.7NH 400MA 100 MOHM	9136
ELL-VGG470M Panasonic	FIXED IND 47UH 270MA 2.1 OHM SMD	1105
ELJ-DA820JF Panasonic	FIXED IND 82UH 80MA 10 OHM SMD	210
ETQ-PAF2R7HFA Panasonic	FIXED IND 2.7UH 17.5A 1.56 MOHM	145
ELL-ATV3R3N Panasonic	FIXED IND 3.3UH 5.35A 8.8 MOHM	8
ELG-TEA1R0NA Panasonic	FIXED IND 1UH 1A 150 MOHM SMD	4
ELJ-RF1N0DF Panasonic	FIXED IND 1NH 400MA 50 MOHM SMD	0
ELC-3GN1R0N Panasonic	FIXED IND 1UH 1.3A 64 MOHM SMD	7633
ETQ-P3M1R5KVP Panasonic	FIXED IND 1.5UH 8.1A 13.2 MOHM	44
ELJ-RF39NJFB Panasonic	FIXED IND 39NH 150MA 1.7 OHM SMD	20731
ELL-5PM390M Panasonic	FIXED IND 39UH 480MA 390 MOHM	1956
ELL-8TP102MB Panasonic	FIXED IND 1MH 330MA 2.1 OHM SMD	0
ELC-18E392L Panasonic	FIXED IND 3.9MH 500MA 1.1 OHM TH	0
ELT-3KN111B Panasonic	FIXED IND 7.5MH 10MA 177 OHM SMD	0
ELT-3KN018B Panasonic	FIXED IND 35MH 1.9MA 235 OHM SMD	0
ELC-15E101L Panasonic	FIXED IND 100UH 3A 53 MOHM TH	3
ELC-10E332L Panasonic	FIXED IND 3.3MH 170MA 5.9 OHM TH	0
ELL-6SH471M Panasonic	FIXED IND 470UH 200MA 3.2 OHM	0
ELL-6PM1R5N Panasonic	FIXED IND 1.5UH 2.45A 20 MOHM	0
ELL-8TP331MB Panasonic	FIXED IND 330UH 570MA 700 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