Fixed Inductors

Part Number	Description / PDF	Quantity
74479298222 Würth Elektronik Midcom	FIXED IND 2.2UH 1.8A 110 MOHM	0
744750460150 Würth Elektronik Midcom	FIXED IND 15UH 9A 12 MOHM TH	25
744062220 Würth Elektronik Midcom	FIXED IND 22UH 1.22A 120 MOHM	352
744771147 Würth Elektronik Midcom	FIXED IND 47UH 2.21A 75 MOHM SMD	10991
744031003 Würth Elektronik Midcom	FIXED IND 3.6UH 1.38A 85 MOHM	1000
74404063100 Würth Elektronik Midcom	FIXED IND 10UH 1.95A 72 MOHM SMD	1411
74404084033 Würth Elektronik Midcom	FIXED IND 3.3UH 4.4A 17 MOHM SMD	1942
744766056 Würth Elektronik Midcom	FIXED IND 5.6UH 300MA 1.1 OHM	0
74405042022 Würth Elektronik Midcom	FIXED IND 2.2UH 2.6A 48 MOHM SMD	2207
74479876215C Würth Elektronik Midcom	FIXED IND 1.5UH 1.5A 115 MOHM	681
74404084150 Würth Elektronik Midcom	FIXED IND 15UH 2.6A 47 MOHM SMD	744
7445120 Würth Elektronik Midcom	FIXED IND 100UH 300MA 480 MOHM	2294
744917151 Würth Elektronik Midcom	FIXED IND 51NH 660MA 280 MOHM	0
744900010 Würth Elektronik Midcom	FIXED IND 1NH 300MA 300 MOHM SMD	0
74431435012 Würth Elektronik Midcom	FIXED IND 120NH 31A 0.28MOHM SMD	1200
74458133 Würth Elektronik Midcom	FIXED IND 33UH 3A 66 MOHM SMD	424
7447669168 Würth Elektronik Midcom	FIXED IND 68UH 350MA 2.25 OHM	1
744918242 Würth Elektronik Midcom	FIXED IND 422NH 2.5A 60 MOHM SMD	1473
744771156 Würth Elektronik Midcom	FIXED IND 56UH 2.01A 110 MOHM	0
744760033A Würth Elektronik Midcom	FIXED IND 3.3NH 800MA 80 MOHM	2336

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