Fixed Inductors

Part Number	Description / PDF	Quantity
B82473M1104K000 TDK EPCOS	FIXED IND 100UH 720MA 430 MOHM	0
B82475A1104K000 TDK EPCOS	FIXED IND 100UH 970MA 350 MOHM	0
B82145A1475J000 TDK EPCOS	FIXED IND 4.7MH 170MA 18 OHM TH	1561
B82442T1124K000 TDK EPCOS	FIXED IND 120UH 440MA 1.29 OHM	0
B82422T1821K000 TDK EPCOS	FIXED IND 820NH 450MA 380 MOHM	0
B82479A1473M000 TDK EPCOS	FIXED IND 47UH 2.6A 87 MOHM SMD	269
B82498F3271J001 TDK EPCOS	FIXED IND 270NH 270MA 1 OHM SMD	6211
B82479A1333M000 TDK EPCOS	FIXED IND 33UH 3A 66 MOHM SMD	0
B82432T1563K000 TDK EPCOS	FIXED IND 56UH 300MA 2 OHM SMD	5160
B78108S1155J009 TDK EPCOS	FIXED IND 1.5MH 100MA 23 OHM TH	0
B82462G4103M000 TDK EPCOS	FIXED IND 10UH 1.5A 62 MOHM SMD	2652
B82559B2102A016 TDK EPCOS	FIXED IND 1UH 36A 1 MOHM SMD	599
B82464A4103M000 TDK EPCOS	FIXED IND 10UH 2.9A 38 MOHM SMD	696
B82472D6103M000 TDK EPCOS	FIXED IND 10UH 2.3A 105 MOHM SMD	0
B82422A1392K100 TDK EPCOS	FIXED IND 3.9UH 190MA 1.4 OHM	0
B82498F3561G000 TDK EPCOS	FIXED IND 560NH 230MA 1.3 OHM	0
B82144F2393J000 TDK EPCOS	FIXED IND 39UH 1.75A 250 MOHM TH	1302
B82144B2822K000 TDK EPCOS	FIXED IND 8.2UH 2.65A 105 MOHM	991
B82498F3100J001 TDK EPCOS	FIXED IND 10NH 700MA 90 MOHM SMD	0
B82442H1184K000 TDK EPCOS	FIXED IND 180UH 270MA 2.24 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