Fixed Inductors

Part Number	Description / PDF	Quantity
74434301008220 Würth Elektronik Midcom	FIXED IND 22UH 2A 104MOHM SMD	490
74479976210 Würth Elektronik Midcom	FIXED IND 1UH 1.8A 93 MOHM SMD	0
74404084330 Würth Elektronik Midcom	FIXED IND 33UH 1.8A 97 MOHM SMD	0
784775133 Würth Elektronik Midcom	FIXED IND 33UH 1.35A 130 MOHM	0
744765122GA Würth Elektronik Midcom	FIXED IND 22NH 400MA 300MOHM SMD	1869
744760310C Würth Elektronik Midcom	FIXED IND 1UH 150MA 4.2 OHM SMD	3384
S14100033 Würth Elektronik Midcom	FIXED IND 15UH 15A 5 MOHM TH	23
7447840022 Würth Elektronik Midcom	FIXED IND 2.2NH 300MA 150 MOHM	9332
744916119 Würth Elektronik Midcom	FIXED IND 19NH 850MA 175 MOHM	0
7447452683 Würth Elektronik Midcom	FIXED IND 68MH 50MA 106 OHM TH	34
7447840147 Würth Elektronik Midcom	FIXED IND 47NH 200MA 1.15 OHM	5505
744786239A Würth Elektronik Midcom	FIXED IND 390NH 150MA 3.2 OHM	0
74408941089 Würth Elektronik Midcom	FIXED IND 8.9UH 950MA 240 MOHM	0
74404052100 Würth Elektronik Midcom	FIXED IND 10UH 1.6A 109 MOHM SMD	725
7447745022 Würth Elektronik Midcom	FIXED IND 2.2UH 3.6A 36 MOHM SMD	935
74476010C Würth Elektronik Midcom	FIXED IND 10NH 600MA 120 MOHM	1810
744373965120 Würth Elektronik Midcom	FIXED IND 12UH 8.2A 20 MOHM SMD	0
744765210A Würth Elektronik Midcom	FIXED IND 100NH 100MA 2.52 OHM	6097
7443550480 Würth Elektronik Midcom	FIXED IND 4.8UH 11A 10.5 MOHM	1111
744062221 Würth Elektronik Midcom	FIXED IND 220UH 360MA 1.1 OHM	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