Fixed Inductors

Part Number	Description / PDF	Quantity
B82472P6684M000 TDK EPCOS	FIXED IND 680UH 250MA 2.75 OHM	795
B82422T1392K000 TDK EPCOS	FIXED IND 3.9UH 250MA 1.3 OHM	0
B82496C3221G000 TDK EPCOS	FIXED IND 220NH 110MA 7 OHM SMD	7485
B82144F2683J000 TDK EPCOS	FIXED IND 68UH 1.5A 350 MOHM TH	3133
B82442A1103K000 TDK EPCOS	FIXED IND 10UH 690MA 168 MOHM	0
B82111B0000C018 TDK EPCOS	FIXED IND 11UH 4A 20 MOHM TH	0
B82134A5202M000 TDK EPCOS	FIXED IND 20UH 2A 150 MOHM TH	860
B82496C3129Z000 TDK EPCOS	FIXED IND 1.2NH 1.8A 25 MOHM SMD	5773
B82477D4683M000 TDK EPCOS	FIXED IND 68UH 1.55A 215 MOHM	0
B82111B0000C021 TDK EPCOS	FIXED IND 5UH 10A 5 MOHM TH	0
B82498F3221G000 TDK EPCOS	FIXED IND 220NH 320MA 700 MOHM	0
B82145A1685J000 TDK EPCOS	FIXED IND 6.8MH 130MA 28.5 OHM	0
B82432T1684K000 TDK EPCOS	FIXED IND 680UH 80MA 23 OHM SMD	4481
B82145A1224J000 TDK EPCOS	FIXED IND 220UH 690MA 1.1 OHM TH	0
B82144A2102K009 TDK EPCOS	FIXED IND 1UH 2.2A 80 MOHM TH	0
B82422A1393K100 TDK EPCOS	FIXED IND 39UH 90MA 6.3 OHM SMD	0
B82422H1473K000 TDK EPCOS	FIXED IND 47UH 230MA 2.1 OHM SMD	45632
B82562N4333M000 TDK EPCOS	FIXED IND 33UH 1.6A 100 MOHM SMD	0
B82422A3181K100 TDK EPCOS	FIXED IND 180NH 360MA 380 MOHM	0
B82498F3221G001 TDK EPCOS	FIXED IND 220NH 320MA 700 MOHM	0

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