Fixed Inductors

Part Number	Description / PDF	Quantity
768772222 Würth Elektronik Midcom	FIXED IND 2.2MH 320MA 4.73 OHM	95
7447471101 Würth Elektronik Midcom	FIXED IND 100UH 1.6A 190 MOHM TH	466
74404084068 Würth Elektronik Midcom	FIXED IND 6.8UH 3.6A 24 MOHM SMD	1315
7440520012 Würth Elektronik Midcom	FIXED IND 1.2UH 3A 30 MOHM SMD	526
744052003 Würth Elektronik Midcom	FIXED IND 3UH 2.2A 45 MOHM SMD	2309
744916124 Würth Elektronik Midcom	FIXED IND 24NH 700MA 290 MOHM	0
744772100 Würth Elektronik Midcom	FIXED IND 10UH 4.2A 40 MOHM TH	1170
784776115 Würth Elektronik Midcom	FIXED IND 15UH 2.47A 80 MOHM SMD	0
784774182 Würth Elektronik Midcom	FIXED IND 82UH 600MA 600 MOHM	0
74477720 Würth Elektronik Midcom	FIXED IND 100UH 790MA 610 MOHM	12234
784777471 Würth Elektronik Midcom	FIXED IND 470UH 350MA 2.72 OHM	0
7443763540068 Würth Elektronik Midcom	FIXED IND 6.8UH 56.7A 1.2 MOHM	48
74402800015 Würth Elektronik Midcom	FIXED IND 150NH 3A 25 MOHM SMD	1257
744778910 Würth Elektronik Midcom	FIXED IND 10UH 1.83A 72 MOHM SMD	7858
744774212 Würth Elektronik Midcom	FIXED IND 120UH 490MA 930 MOHM	1474
744901118 Würth Elektronik Midcom	FIXED IND 18NH 100MA 2 OHM SMD	0
744045006 Würth Elektronik Midcom	FIXED IND 6.8UH 1.1A 200 MOHM	266
74470292 Würth Elektronik Midcom	FIXED IND 130UH 3A 90 MOHM TH	93
7843340047 Würth Elektronik Midcom	FIXED IND 470NH 19A 2.8MOHM SMD	0
744784133A Würth Elektronik Midcom	FIXED IND 33NH 200MA 800 MOHM	7278

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