Fixed Inductors

Part Number	Description / PDF	Quantity
B82145A1104J000 TDK EPCOS	FIXED IND 100UH 860MA 700 MOHM	2196
B82422T1223K008 TDK EPCOS	FIXED IND 22UH 110MA 3.5 OHM SMD	0
B82144F1106J000 TDK EPCOS	FIXED IND 10MH 85MA 42 OHM TH	0
B82562N4472N000 TDK EPCOS	FIXED IND 4.7UH 3.3A 23 MOHM SMD	0
B78108E1151M000 TDK EPCOS	FIXED IND 150NH 6.5A 17 MOHM TH	4198
B82144F2472K000 TDK EPCOS	FIXED IND 4.7UH 3.05A 80 MOHM TH	1883
B82464G4102M000 TDK EPCOS	FIXED IND 1UH 7.5A 7 MOHM SMD	1497
B82498F3271G001 TDK EPCOS	FIXED IND 270NH 270MA 1 OHM SMD	0
B82422T3101J000 TDK EPCOS	FIXED IND 100NH 450MA 310 MOHM	0
B82498F3820G001 TDK EPCOS	FIXED IND 82NH 500MA 190 MOHM	0
B82473M1333K000 TDK EPCOS	FIXED IND 33UH 1.2A 130 MOHM SMD	0
B82141A1224J000 TDK EPCOS	FIXED IND 220UH 130MA 5.8 OHM TH	0
B82498F3471G000 TDK EPCOS	FIXED IND 470NH 190MA 1.9 OHM	3844
B82442H1472K000 TDK EPCOS	FIXED IND 4.7UH 1.35A 88 MOHM	7278
B82432C1124K000 TDK EPCOS	FIXED IND 120UH 140MA 5.2 OHM	0
B82559A0501A013 TDK EPCOS	FIXED IND 500NH 30A 0.78 MOHM	1057
B82422T1103K008 TDK EPCOS	FIXED IND 10UH 150MA 2.1 OHM SMD	0
B82471A1473M000 TDK EPCOS	FIXED IND 47UH 720MA 370 MOHM	0
B82432C1152K000 TDK EPCOS	FIXED IND 1.5UH 535MA 350 MOHM	0
B78148E1681M009 TDK EPCOS	FIXED IND 680NH 4.6A 31 MOHM TH	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