Fixed Inductors

Part Number	Description / PDF	Quantity
B82442T1825J000 TDK EPCOS	FIXED IND 8.2MH 54MA 80.6 OHM	0
B82144A2683J000 TDK EPCOS	FIXED IND 68UH 700MA 600 MOHM TH	0
B82442H1394J000 TDK EPCOS	FIXED IND 390UH 180MA 4.64 OHM	0
B78108S1563J000 TDK EPCOS	FIXED IND 56UH 430MA 1.23 OHM TH	10000
B82442T1103K050 TDK EPCOS	FIXED IND 10UH 1.42A 132 MOHM	2430
B82422T1471J008 TDK EPCOS	FIXED IND 470NH 450MA 300 MOHM	0
B78148S1153K009 TDK EPCOS	FIXED IND 15UH 610MA 600 MOHM TH	0
B82141A1683J000 TDK EPCOS	FIXED IND 68UH 185MA 2.9 OHM TH	0
B825620B977K882 TDK EPCOS	FIXED IND	0
B82422T1472K000 TDK EPCOS	FIXED IND 4.7UH 220MA 1.5 OHM	7188
B82422T3820J000 TDK EPCOS	FIXED IND 82NH 450MA 260 MOHM	0
B82472G4104M000 TDK EPCOS	FIXED IND 100UH 560MA 700 MOHM	2337
B82498F1392J000 TDK EPCOS	FIXED IND 3.9UH 95MA 3.6 OHM SMD	0
B82144B1333J000 TDK EPCOS	FIXED IND 33UH 1.1A 350 MOHM TH	0
B82559A3152A016 TDK EPCOS	FIXED IND 1.5UH 33A 1.6 MOHM	116
B82559A7103A025 TDK EPCOS	FIXED IND 10UH 2.2 MOHM SMD	1867
B82496C3829J000 TDK EPCOS	FIXED IND 8.2NH 650MA 180 MOHM	6435
B82453C0335A022 TDK EPCOS	FIXED INDUCTOR	0
B82144A2224J000 TDK EPCOS	FIXED IND 220UH 400MA 1.6 OHM TH	107
B78108S1223K000 TDK EPCOS	FIXED IND 22UH 560MA 740 MOHM TH	2181

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