Fixed Inductors

Part Number	Description / PDF	Quantity
ELL-6GM180M Panasonic	FIXED IND 18UH 710MA 260 MOHM	637
ETQ-P5M100YFM Panasonic	FIXED IND 10UH 5.7A 41.3 MOHM	4744
ELL-6PV680M Panasonic	FIXED IND 68UH 420MA 570 MOHM	824
ETQ-P4M6R8KVK Panasonic	FIXED IND 6.8UH 6.9A 25.85 MOHM	338
ETQ-P5M220YFM Panasonic	FIXED IND 22UH 3.7A 102MOHM SMD	2
ELJ-PF8N2JF Panasonic	FIXED IND 8.2NH 900MA 210 MOHM	4447
ELJ-QF1N6ZF Panasonic	FIXED IND 1.6NH 400MA 80 MOHM	17976
ELJ-PF6N8JFB Panasonic	FIXED IND 6.8NH 1.1A 160 MOHM	640
ETQ-P4M3R3YFN Panasonic	FIXED IND 3.3UH 8.2A 17.71 MOHM	643
ELJ-QF3N9ZF Panasonic	FIXED IND 3.9NH 360MA 150 MOHM	16995
ETQ-P8MR68JFA Panasonic	FIXED IND 680NH 35.4A 1.21 MOHM	363
ELG-TEA3R3NA Panasonic	FIXED IND 3.3UH 800MA 250 MOHM	609
ELC-18E680 Panasonic	FIXED IND 68UH 3.6A 36 MOHM TH	0
ELL-VFG6R8NC Panasonic	FIXED IND 6.8UH 840MA 230 MOHM	2015
ELJ-QF9N1ZF Panasonic	FIXED IND 9.1NH 320MA 380 MOHM	1706
ELJ-FB121JF Panasonic	FIXED IND 120UH 100MA 10 OHM SMD	8
ETQ-P5MR68YSC Panasonic	FIXED IND 680NH 32.3A 1.83MOHM	785
ELT-5KN118C Panasonic	FIXED IND 560UH 60MA 6 OHM SMD	0
ELL-6RH4R7M Panasonic	FIXED IND 4.7UH 1.58A 49 MOHM	0
ELJ-ND27NJF Panasonic	FIXED IND 27NH 455MA 340 MOHM	2457

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