Fixed Inductors

Part Number	Description / PDF	Quantity
B82144F2822K000 TDK EPCOS	FIXED IND 8.2UH 2.65A 105 MOHM	0
B82496C3560J000 TDK EPCOS	FIXED IND 56NH 250MA 1.2 OHM SMD	11400
B82422A3271K100 TDK EPCOS	FIXED IND 270NH 235MA 900 MOHM	1431
B82442T1334K050 TDK EPCOS	FIXED IND 330UH 280MA 3.29 OHM	1738
B82144B2393J000 TDK EPCOS	FIXED IND 39UH 1.75A 250 MOHM TH	921
B82498F3689K001 TDK EPCOS	FIXED IND 6.8NH 800MA 50 MOHM	0
B82432C1274J000 TDK EPCOS	FIXED IND 270UH 90MA 12.5 OHM	0
B82432T1102K000 TDK EPCOS	FIXED IND 1UH 1.3A 80 MOHM SMD	0
B82477R4152M100 TDK EPCOS	FIXED IND 1.5UH 9.75A 6.5 MOHM	0
B82422T1331J000 TDK EPCOS	FIXED IND 330NH 450MA 230 MOHM	0
B78148S1225J009 TDK EPCOS	FIXED IND 2.2MH 80MA 34.7 OHM TH	0
B82422H1103K100 TDK EPCOS	FIXED IND 10UH 300MA 1.2 OHM SMD	0
B82442H1154K000 TDK EPCOS	FIXED IND 150UH 290MA 1.76 OHM	0
B78148E1471M000 TDK EPCOS	FIXED IND 470NH 5A 27 MOHM TH	1541
B82422A1822K100 TDK EPCOS	FIXED IND 8.2UH 130MA 3 OHM SMD	8668
B82562N4154M000 TDK EPCOS	FIXED IND 150UH 720MA 480 MOHM	0
B82422A1562K100 TDK EPCOS	FIXED IND 5.6UH 140MA 2.6 OHM	5727
B82442T1155J50 TDK EPCOS	FIXED IND 1.5MH 130MA 14.9 OHM	0
B82422T1471J000 TDK EPCOS	FIXED IND 470NH 450MA 300 MOHM	0
B82442A1474J000 TDK EPCOS	FIXED IND 470UH 120MA 5.6 OHM	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