Fixed Inductors

Part Number	Description / PDF	Quantity
74437349010 Würth Elektronik Midcom	FIXED IND 1UH 10A 6.5 MOHM SMD	712
7447715906 Würth Elektronik Midcom	FIXED IND 600NH 9.5A 5.5 MOHM	0
74479262210 Würth Elektronik Midcom	FIXED IND 1UH 1.2A 195 MOHM SMD	0
74437324047 Würth Elektronik Midcom	FIXED IND 4.7UH 2.2A 105 MOHM	3048
7447713150 Würth Elektronik Midcom	FIXED IND 15UH 2.2A 89 MOHM SMD	800
744029000068 Würth Elektronik Midcom	FIXED IND 68NH 4.5A 15 MOHM SMD	990
78477410 Würth Elektronik Midcom	FIXED IND 10UH 2.2A 100 MOHM SMD	0
7440430018 Würth Elektronik Midcom	FIXED IND 1.8UH 2.7A 25 MOHM SMD	222
74457068 Würth Elektronik Midcom	FIXED IND 6.8UH 7.5A 17 MOHM SMD	0
7447789156 Würth Elektronik Midcom	FIXED IND 56UH 840MA 470 MOHM	650
7447471033 Würth Elektronik Midcom	FIXED IND 3.3UH 7.5A 10.6 MOHM	30
744762168A Würth Elektronik Midcom	FIXED IND 68NH 1A 150 MOHM SMD	2319
7443762504068 Würth Elektronik Midcom	FIXED IND 6.8UH 20A 4.63 MOHM TH	200
78438322010 Würth Elektronik Midcom	FIXED IND 1UH 1.75A 133 MOHM SMD	0
7847709102 Würth Elektronik Midcom	FIXED IND 1MH 630MA 1.06 OHM SMD	0
744105 Würth Elektronik Midcom	FIXED IND 258UH 1.2A 400 MOHM TH	0
7447649015 Würth Elektronik Midcom	FIXED IND 1.5UH 1.4A 195 MOHM	0
74408942220 Würth Elektronik Midcom	FIXED IND 22UH 850MA 354 MOHM	290
784771082 Würth Elektronik Midcom	FIXED IND 8.2UH 5.05A 24 MOHM	0
744741101 Würth Elektronik Midcom	FIXED IND 100UH 1.1A 1 OHM TH	4

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