Fixed Inductors

Part Number	Description / PDF	Quantity
B82111E0000C025 TDK EPCOS	FIXED IND 100UH 1A 650 MOHM TH	6743
B82498F3471J000 TDK EPCOS	FIXED IND 470NH 190MA 1.9 OHM	43
B82141A1102K000 TDK EPCOS	FIXED IND 1UH 725MA 190 MOHM TH	0
B82442H1153K000 TDK EPCOS	FIXED IND 15UH 810MA 240 MOHM	4847
B82464G4153M000 TDK EPCOS	FIXED IND 15UH 2.75A 40 MOHM SMD	1585
B82472G6224M000 TDK EPCOS	FIXED IND 220UH 430MA 880 MOHM	1491
B82500C0000A002 TDK EPCOS	FIXED IND 3.9MH 200MA 20 OHM TH	488
B82472G6222M000 TDK EPCOS	FIXED IND 2.2UH 3A 20 MOHM SMD	1973
B82442A1565K000 TDK EPCOS	FIXED IND 5.6MH 33MA 68 OHM SMD	0
B82422T3470K000 TDK EPCOS	FIXED IND 47NH 450MA 200 MOHM	0
B78108S1333K009 TDK EPCOS	FIXED IND 33UH 500MA 920 MOHM TH	0
B82144A2332K000 TDK EPCOS	FIXED IND 3.3UH 1.75A 130 MOHM	0
B82496C3101J000 TDK EPCOS	FIXED IND 100NH 200MA 1.8 OHM	4927
B82477P2103M000 TDK EPCOS	FIXED IND 10UH 4.3A 25 MOHM SMD	1030
B82482M1821N000 TDK EPCOS	PCM120T-R82N-D; 12.4X13.1X11.5 M	0
B82477G2223M000 TDK EPCOS	FIXED IND 22UH 2.8A 36 MOHM SMD	808
B82472G4103M000 TDK EPCOS	FIXED IND 10UH 1.7A 80 MOHM SMD	117
B82464A4472M000 TDK EPCOS	FIXED IND 4.7UH 4.3A 18 MOHM SMD	1467
B82141A1104K009 TDK EPCOS	FIXED IND 100UH 170MA 3.5 OHM TH	0
B82559B0203A019 TDK EPCOS	FIXED IND 20UH 9.5A 13.5 MOHM	400

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