Fixed Inductors

Part Number	Description / PDF	Quantity
B82144F2154J000 TDK EPCOS	FIXED IND 150UH 1.05A 700 MOHM	0
B82432C1563K000 TDK EPCOS	FIXED IND 56UH 200MA 2.5 OHM SMD	0
B82111B0000C017 TDK EPCOS	FIXED IND 6UH 6A 10 MOHM TH	1890
B82442A1823K000 TDK EPCOS	FIXED IND 82UH 270MA 1.12 OHM	0
B82472G4474M000 TDK EPCOS	FIXED IND 470UH 260MA 2.7 OHM	994
B82134A5401M000 TDK EPCOS	FIXED IND 150UH 400MA 3.5 OHM TH	764
B82144B2474J000 TDK EPCOS	FIXED IND 470UH 600MA 2.02 OHM	846
B82477D4223M900 TDK EPCOS	FIXED IND 22UH 3.11A 78 MOHM SMD	350
B82475A1683K000 TDK EPCOS	FIXED IND 68UH 1.11A 220 MOHM	0
B82144A2333J000 TDK EPCOS	FIXED IND 33UH 900MA 430 MOHM TH	0
B82442A1333J000 TDK EPCOS	FIXED IND 33UH 400MA 500 MOHM	0
B82477P4104M000 TDK EPCOS	FIXED IND 100UH 1.87A 138 MOHM	614
B82422H1334K000 TDK EPCOS	FIXED IND 330UH 90MA 13 OHM SMD	991
B82559A9103A024 TDK EPCOS	FIXED IND 10UH 32.1A 1.85 MOHM	175
B82144B2222K000 TDK EPCOS	FIXED IND 2.2UH 3.65A 55 MOHM TH	884
B78108S1225J000 TDK EPCOS	FIXED IND 2.2MH 80MA 34.7 OHM TH	3878
B82442A1154K000 TDK EPCOS	FIXED IND 150UH 210MA 1.76 OHM	0
B78148S1224J000 TDK EPCOS	FIXED IND 220UH 250MA 3.3 OHM TH	0
B82111E0000C024 TDK EPCOS	FIXED IND 56UH 1.5A 300 MOHM TH	1950
B82559B2102A019 TDK EPCOS	FIXED IND 1UH 36.3A 0.95 MOHM	426

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