Fixed Inductors

Part Number	Description / PDF	Quantity
ELJ-QE22NJFA Panasonic	FIXED IND 22NH 290MA 520 MOHM	6233
ELC-18E332 Panasonic	FIXED IND 3.3MH 600MA 1 OHM TH	0
ETQ-P6F0R8LFA Panasonic	FIXED IND 800NH 14.2A 2.24 MOHM	1
ELJ-PB820KF Panasonic	FIXED IND 82UH 160MA 3.5 OHM SMD	657
ELJ-QF15NJF Panasonic	FIXED IND 15NH 240MA 600 MOHM	44473
ELL-4LG470MA Panasonic	FIXED IND 47UH 410MA 920 MOHM	2334
ELC-18E120 Panasonic	FIXED IND 12UH 5.6A 16 MOHM TH	0
ELL-4LG1R0NA Panasonic	FIXED IND 1UH 1.9A 43 MOHM SMD	3735
ELL-VGG3R9N Panasonic	FIXED IND 3.9UH 1A 150 MOHM SMD	1350
ELL-ATV270M Panasonic	FIXED IND 27UH 2A 56 MOHM SMD	4584
ETQ-P5M470YFM Panasonic	FIXED IND 47UH 2.9A 172 MOHM SMD	0
ELJ-RF2N7DFB Panasonic	FIXED IND 2.7NH 400MA 100 MOHM	312373
ELL-ATV561M Panasonic	FIXED IND 560UH 390MA 820 MOHM	121
ELJ-QF27NGF Panasonic	FIXED IND 27NH 200MA 1.2 OHM SMD	17663
ELJ-FCR68MF Panasonic	FIXED IND 680NH 140MA 1.25 OHM	3592
ELC-18E6R8 Panasonic	FIXED IND 6.8UH 6.5A 13 MOHM TH	0
ELL-6RH270M Panasonic	FIXED IND 27UH 650MA 260 MOHM	1803
ELJ-NC56NKF Panasonic	FIXED IND 56NH 200MA 630 MOHM	288
ELJ-RG15NJF Panasonic	FIXED IND 15NH 150MA 2.2 OHM SMD	14678
ELJ-NCR68JF Panasonic	FIXED IND 680NH 110MA 1.85 OHM	354

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