Fixed Inductors

Part Number	Description / PDF	Quantity
ELJ-QF13NGF Panasonic	FIXED IND 13NH 280MA 530 MOHM	6390
ELC-18E102 Panasonic	FIXED IND 1MH 1A 280 MOHM TH	0
ELL-8UV4R7N Panasonic	FIXED IND 4.7UH 4.2MA 12 OHM SMD	305
ELL-5PR1R5N Panasonic	FIXED IND 1.5UH 2.85A 25 MOHM	4230
ETQ-P8M3R3JFA Panasonic	FIXED IND 3.3UH 19.6A 3.96 MOHM	389
ELJ-RF3N3DFB Panasonic	FIXED IND 3.3NH 400MA 120 MOHM	9250
ELC-18E332L Panasonic	FIXED IND 3.3MH 600MA 1 OHM TH	0
ELL-ATV471M Panasonic	FIXED IND 470UH 470MA 780 MOHM	1908
ELL-6GG100M Panasonic	FIXED IND 10UH 1A 170 MOHM SMD	400
ETQ-P5M470YFK Panasonic	FIXED IND 47UH 3.4A 138 MOHM SMD	0
ELJ-RF9N1ZFB Panasonic	FIXED IND 9.1NH 320MA 380 MOHM	7985
ETQ-P5M330YFM Panasonic	FIXED IND 33UH 3.3A 132 MOHM SMD	206
ELL-8TP560MB Panasonic	FIXED IND 56UH SMD	898
ELC-3GN1R6N Panasonic	FIXED IND 1.6UH 1.2A 83 MOHM SMD	991
ELJ-QF9N1JF Panasonic	FIXED IND 9.1NH 320MA 380 MOHM	19692
ELJ-NCR22JF Panasonic	FIXED IND 220NH 145MA 1.15 OHM	539
ETQ-P4M3R3KVC Panasonic	FIXED IND 3.3UH 12.6A 10.34 MOHM	331
ELJ-QF10NJF Panasonic	FIXED IND 10NH 320MA 410 MOHM	43072
ELJ-QE8N2ZFA Panasonic	FIXED IND 8.2NH 490MA 170 MOHM	1883
ETQ-P3W1R0WFN Panasonic	FIXED IND 1UH 13A 7.9 MOHM SMD	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