Fixed Inductors

Part Number	Description / PDF	Quantity
B82422A3221K100 TDK EPCOS	FIXED IND 220NH 280MA 640 MOHM	0
B82442A1104K000 TDK EPCOS	FIXED IND 100UH 250MA 1.28 OHM	1143
B82422A3470J108 TDK EPCOS	FIXED IND 47NH 510MA 190 MOHM	0
B82145A1334J000 TDK EPCOS	FIXED IND 330UH 630MA 1.3 OHM TH	0
B82477D4103M900 TDK EPCOS	FIXED IND 10UH 4.54A 42 MOHM SMD	350
B82442T1393K000 TDK EPCOS	FIXED IND 39UH 720MA 456 MOHM	0
B78108E1682K009 TDK EPCOS	FIXED IND 6.8UH 2.45A 105 MOHM	4770
B82559A0142A013 TDK EPCOS	FIXED IND 1.4UH 22A 1.5 MOHM SMD	2291
B78108E1472K009 TDK EPCOS	FIXED IND 4.7UH 2.75A 85 MOHM TH	3643
B82442A1332K000 TDK EPCOS	FIXED IND 3.3UH 1.12A 64 MOHM	2
B82132A5402M000 TDK EPCOS	FIXED IND 2UH 4A 20 MOHM TH	1644
B82422T3120K000 TDK EPCOS	FIXED IND 12NH 450MA 110 MOHM	0
B82464A4222M000 TDK EPCOS	FIXED IND 2.2UH 5.7A 12 MOHM SMD	0
B78148E1331M009 TDK EPCOS	FIXED IND 330NH 5.3A 23 MOHM TH	0
B82498F3391G001 TDK EPCOS	FIXED IND 390NH 210MA 1.6 OHM	0
B82422H1472K000 TDK EPCOS	FIXED IND 4.7UH 700MA 250 MOHM	9523
B82442T1153K050 TDK EPCOS	FIXED IND 15UH 1.26A 190 MOHM	812
B82496C3220J000 TDK EPCOS	FIXED IND 22NH 380MA 500 MOHM	2745
B82498F3221J000 TDK EPCOS	FIXED IND 220NH 320MA 700 MOHM	0
B82144B2392K000 TDK EPCOS	FIXED IND 3.9UH 3.35A 75 MOHM TH	1878

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