Fixed Inductors

Part Number	Description / PDF	Quantity
B82559A5682A020 TDK EPCOS	FIXED IND 6.8UH 2.9 MOHM SMD	217
B78108S1473J000 TDK EPCOS	FIXED IND 47UH 450MA 1.1 OHM TH	6609
B82422A1152K100 TDK EPCOS	FIXED IND 1.5UH 340MA 500 MOHM	4379
B78108E1222K000 TDK EPCOS	FIXED IND 2.2UH 3.4A 57 MOHM TH	4010
B82442H1334J000 TDK EPCOS	FIXED IND 330UH 200MA 3.92 OHM	0
B82432C1473J000 TDK EPCOS	FIXED IND 47UH 210MA 2.3 OHM SMD	0
B82479A1105M000 TDK EPCOS	FIXED IND 1MH 560MA 1.8 OHM SMD	0
B82477G4224M000 TDK EPCOS	FIXED IND 220UH 1.16A 380 MOHM	881
B82477D6333M603 TDK EPCOS	FIXED IND 33UH 3.22A 75MOHM SMD	239
B82473A1474K000 TDK EPCOS	FIXED IND 470UH 340MA 1.96 OHM	0
B82477G4103M000 TDK EPCOS	FIXED IND 10UH 5.4A 22 MOHM SMD	831
B82464G4821M000 TDK EPCOS	FIXED IND 820NH 7.6A 7 MOHM SMD	0
B82498F3470J000 TDK EPCOS	FIXED IND 47NH 600MA 130 MOHM	1516
B82496C3390G000 TDK EPCOS	FIXED IND 39NH 300MA 800 MOHM	0
B82498F3151J000 TDK EPCOS	FIXED IND 150NH 400MA 420 MOHM	7237
B82422T1153K000 TDK EPCOS	FIXED IND 15UH 130MA 2.8 OHM SMD	3320
B82442T1564K000 TDK EPCOS	FIXED IND 560UH 220MA 5.21 OHM	0
B82144B1103K000 TDK EPCOS	FIXED IND 10UH 1.5A 180 MOHM TH	0
B82422A3471J100 TDK EPCOS	FIXED IND 470NH 150MA 2.2 OHM	3948
B82471A1153M000 TDK EPCOS	FIXED IND 15UH 1.3A 140 MOHM SMD	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