Fixed Inductors

Part Number	Description / PDF	Quantity
B82144F2563J000 TDK EPCOS	FIXED IND 56UH 1.6A 310 MOHM TH	4096
B78148S1223K009 TDK EPCOS	FIXED IND 22UH 560MA 740 MOHM TH	0
B82442H1155J000 TDK EPCOS	FIXED IND 1.5MH 100MA 16 OHM SMD	45
B82422A3220J100 TDK EPCOS	FIXED IND 22NH 600MA 140 MOHM	0
B82144A2155J000 TDK EPCOS	FIXED IND 1.5MH 160MA 6 OHM TH	0
B78148S1475J009 TDK EPCOS	FIXED IND 4.7MH 55MA 78 OHM TH	0
B82422A1103K100 TDK EPCOS	FIXED IND 10UH 180MA 1.6 OHM SMD	0
B82442T1223K000 TDK EPCOS	FIXED IND 22UH 1.04A 238 MOHM	0
B82422H1224J000 TDK EPCOS	FIXED IND 220UH 100MA 10.9 OHM	1524
B82496C3159A000 TDK EPCOS	FIXED IND 1.5NH 1.5A 30 MOHM SMD	2722
B82464P4104M000 TDK EPCOS	FIXED IND 100UH 1.05A 220 MOHM	196
B82462G4152M000 TDK EPCOS	FIXED IND 1.5UH 3.1A 20 MOHM SMD	1807
B82442A1155J000 TDK EPCOS	FIXED IND 1.5MH 70MA 16 OHM SMD	0
B82472G6683M000 TDK EPCOS	FIXED IND 68UH 820MA 260 MOHM	950
B82476B1105M100 TDK EPCOS	FIXED IND 1MH 330MA 2.15 OHM SMD	738
B82144F2392K000 TDK EPCOS	FIXED IND 3.9UH 3.35A 75 MOHM TH	915
B82442T1224K000 TDK EPCOS	FIXED IND 220UH 330MA 2.21 OHM	0
B82131A5202M000 TDK EPCOS	FIXED IND 3UH 2A 90 MOHM TH	1489
B82144F1333J000 TDK EPCOS	FIXED IND 33UH 1.1A 350 MOHM TH	0
B82432C1472K000 TDK EPCOS	FIXED IND 4.7UH 390MA 650 MOHM	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