Fixed Inductors

Part Number	Description / PDF	Quantity
B82442A1223K000 TDK EPCOS	FIXED IND 22UH 480MA 350 MOHM	2364
B82422T1153J000 TDK EPCOS	FIXED IND 15UH 130MA 2.8 OHM SMD	0
B82144A2223K009 TDK EPCOS	FIXED IND 22UH 1.1A 350 MOHM TH	0
B82477R4684M100 TDK EPCOS	FIXED IND 680UH 880MA 860 MOHM	0
B82422A1103K108 TDK EPCOS	FIXED IND 10UH 180MA 1.6 OHM SMD	0
B82477P2333M000 TDK EPCOS	FIXED IND 33UH 2.7A 55 MOHM SMD	513
B82422A3150J100 TDK EPCOS	FIXED IND 15NH 640MA 120 MOHM	0
B82422T1183K000 TDK EPCOS	FIXED IND 18UH 120MA 3 OHM SMD	0
B82442A1824K000 TDK EPCOS	FIXED IND 820UH 90MA 10.4 OHM	0
B82141A1183K000 TDK EPCOS	FIXED IND 18UH 350MA 810 MOHM TH	0
B82559A4222A016 TDK EPCOS	FIXED IND 2.2UH 30A 2.1 MOHM	353
B82482M1102N000 TDK EPCOS	PCM120T-1R0N-D; 12.4X13.1X11.5 M	0
B82477R4153M100 TDK EPCOS	FIXED IND 15UH 5A 25 MOHM SMD	699
B82422A1472K108 TDK EPCOS	FIXED IND 4.7UH 150MA 2.2 OHM	0
B78108E1153K009 TDK EPCOS	FIXED IND 15UH 1.6A 230 MOHM TH	5221
B82559A2122A025 TDK EPCOS	FIXED IND 1.25UH 0.4 MOHM SMD	662
B82144B1472K000 TDK EPCOS	FIXED IND 4.7UH 1.8A 120 MOHM TH	0
B82442H1473K000 TDK EPCOS	FIXED IND 47UH 480MA 680 MOHM	10384
B82432T1123K000 TDK EPCOS	FIXED IND 12UH 630MA 450 MOHM	0
B82464G4104M000 TDK EPCOS	FIXED IND 100UH 1.05A 220 MOHM	1783

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