Fixed Inductors

Part Number	Description / PDF	Quantity
74456215 Würth Elektronik Midcom	FIXED IND 150UH 1A 590 MOHM SMD	1115
744760410A Würth Elektronik Midcom	FIXED IND 10UH 80MA 5 OHM SMD	1459
744787330 Würth Elektronik Midcom	FIXED IND 33UH 1.48A 161 MOHM	837
744062150 Würth Elektronik Midcom	FIXED IND 15UH 1.31A 95 MOHM SMD	256
744373360047 Würth Elektronik Midcom	FIXED IND 470NH 9.2A 7.4 MOHM	200
744917111 Würth Elektronik Midcom	FIXED IND 11NH 1.4A 58 MOHM SMD	0
744325780 Würth Elektronik Midcom	FIXED IND 7.8UH 8A 13.6 MOHM SMD	1679
7443762504100 Würth Elektronik Midcom	FIXED IND 10UH 20A 4.63 MOHM TH	200
74479157 Würth Elektronik Midcom	FIXED IND 2.7UH 50MA 600 MOHM	400
S14100032 Würth Elektronik Midcom	FIXED IND 150UH 10A 21 MOHM TH	49
74437349022 Würth Elektronik Midcom	FIXED IND 2.2UH 7.5A 12 MOHM SMD	471
74435572200 Würth Elektronik Midcom	FIXED IND 22UH 11A 14.6 MOHM SMD	1085
744304010 Würth Elektronik Midcom	FIXED IND 100NH 24A 0.17 MOHM	0
78438321010 Würth Elektronik Midcom	FIXED IND 1UH 1.25A 196 MOHM SMD	0
744028003 Würth Elektronik Midcom	FIXED IND 3.3UH 1A 220 MOHM SMD	211
744771118 Würth Elektronik Midcom	FIXED IND 18UH 3.48A 34 MOHM SMD	0
744786015A Würth Elektronik Midcom	FIXED IND 1.5NH 600MA 100 MOHM	66
7847709221 Würth Elektronik Midcom	FIXED IND 220UH 1.45A 245 MOHM	0
7449150046 Würth Elektronik Midcom	FIXED IND 46.5NH 28A 1.62 MOHM	1305
744786127A Würth Elektronik Midcom	FIXED IND 27NH 400MA 650 MOHM	3970

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