Fixed Inductors

Part Number	Description / PDF	Quantity
ELL-4LG2R7NA Panasonic	FIXED IND 2.7UH 1.55A 63 MOHM	2130
ELJ-QF7N5JF Panasonic	FIXED IND 7.5NH 320MA 330 MOHM	18635
ELJ-PF3N3DF Panasonic	FIXED IND 3.3NH 1.5A 70 MOHM SMD	16957
ELJ-QF4N7DF Panasonic	FIXED IND 4.7NH 360MA 170 MOHM	41817
ELJ-PF5N6DF Panasonic	FIXED IND 5.6NH 1.2A 120 MOHM	4528
ELL-SFG101MA Panasonic	FIXED IND 100UH 240MA 2.4 OHM	3913
ELC-18E272 Panasonic	FIXED IND 2.7MH 650MA 890 MOHM	0
ETQ-P4M2R2KVC Panasonic	FIXED IND 2.2UH 14.8A 7.48 MOHM	101
ELC-18E101 Panasonic	FIXED IND 100UH 3A 44 MOHM TH	0
ELL-4GG3R9N Panasonic	FIXED IND 3.9UH 1.15A 120 MOHM	649
ETQ-P4M1R5KVC Panasonic	FIXED IND 1.5UH 17.4A 5.39 MOHM	384
ETQ-P5MR33YLC Panasonic	FIXED IND 330NH 39.7A 1.21 MOHM	1272
ELL-CTV391M Panasonic	FIXED IND 390UH 630MA 560 MOHM	98
ETQ-P3M3R3KVP Panasonic	FIXED IND 3.3UH 5.4A 30.03 MOHM	0
ELJ-NA1R8JF Panasonic	FIXED IND 1.8UH 110MA 3 OHM SMD	4572
ELC-18E103L Panasonic	FIXED IND 10MH 330MA 2.7 OHM TH	0
ETQ-P4M150KFN Panasonic	FIXED IND 15UH 4.2A 70.18 MOHM	0
ELL-6RH5R1M Panasonic	FIXED IND 5.1UH 1.55A 56 MOHM	13
ELJ-QF22NJF Panasonic	FIXED IND 22NH 200MA 800 MOHM	9737
ELL-8UV7R5N Panasonic	FIXED INDUCTOR 7.5UH SMD	999

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