Fixed Inductors

Part Number	Description / PDF	Quantity
ELL-4LG3R3NA Panasonic	FIXED IND 3.3UH 1.45A 72 MOHM	0
ELC-18E122 Panasonic	FIXED IND 1.2MH 950MA 360 MOHM	0
ETQ-P5M4R7YFC Panasonic	FIXED IND 4.7UH 13.1A 11.3 MOHM	286
ELJ-PE3N9KF Panasonic	FIXED IND 3.9NH 2.1A 40 MOHM SMD	5307
ELJ-PF2N2DF Panasonic	FIXED IND 2.2NH 1.9A 40 MOHM SMD	5630
ETQ-P5M100YFK Panasonic	FIXED IND 10UH 6.7A 37 MOHM SMD	23
ELL-4GG1R8N Panasonic	FIXED IND 1.8UH 1.55A 71 MOHM	2714
ETQ-P3H0R8BFA Panasonic	FIXED IND 800NH 16A 2.33 MOHM	492
ETQ-P4M330KVK Panasonic	FIX IND 33UH 3.1A SMD	8
ETQ-P3M100HFN Panasonic	FIXED IND 10UH 3.7A 74.8 MOHM	0
ELC-18E222 Panasonic	FIXED IND 2.2MH 730MA 630 MOHM	0
ELJ-FC120JF Panasonic	FIXED IND 12UH 75MA 4.1 OHM SMD	3
ELJ-FA2R7KF Panasonic	FIXED IND 2.7UH 180MA 1.1 OHM	9973
ELT-5KN120C Panasonic	FIXED IND 2.7MH 35MA 33 OHM SMD	0
ELJ-QF5N6ZF Panasonic	FIXED IND 5.6NH 340MA 190 MOHM	12474
ELJ-RF8N2JF Panasonic	FIXED IND 8.2NH 320MA 350 MOHM	42591
ETQ-P5M1R0YLC Panasonic	FIXED IND 1UH 27.5A 2.53 MOHM	1602
ELL-6PM5R6N Panasonic	FIXED IND 5.6UH 1.5A 52 MOHM SMD	30
ELT-5KT100MC Panasonic	FIXED IND 10UH 680MA 360 MOHM	5086
ELJ-RF27NJFB Panasonic	FIXED IND 27NH 200MA 1.2 OHM SMD	14

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