Fixed Inductors

Part Number	Description / PDF	Quantity
B82442H1225K000 TDK EPCOS	FIXED IND 2.2MH 75MA 28 OHM SMD	3928
B82442H1683K000 TDK EPCOS	FIXED IND 68UH 400MA 960 MOHM	0
B82562N4153M000 TDK EPCOS	FIXED IND 15UH 2A 60 MOHM SMD	0
B82496C3479J000 TDK EPCOS	FIXED IND 4.7NH 800MA 100 MOHM	11678
B78108S1222K000 TDK EPCOS	FIXED IND 2.2UH 1A 250 MOHM TH	6084
B82475A1334K000 TDK EPCOS	FIXED IND 330UH 520MA 1.15 OHM	0
B78108S1275J000 TDK EPCOS	FIXED IND 2.7MH 75MA 40 OHM TH	0
B82422T1102K000 TDK EPCOS	FIXED IND 1UH 400MA 600 MOHM SMD	5135
B82559A0353A020 TDK EPCOS	FIXED IND 35UH 7 MOHM SMD	37
B82422H1334J000 TDK EPCOS	FIXED IND 330UH 90MA 13 OHM SMD	1896
B82422A1332K100 TDK EPCOS	FIXED IND 3.3UH 200MA 1.2 OHM	5078
B82141A1223K009 TDK EPCOS	FIXED IND 22UH 335MA 900 MOHM TH	0
B82473M1103K000 TDK EPCOS	FIXED IND 10UH 2.3A 70 MOHM SMD	0
B82111E0000C022 TDK EPCOS	FIXED IND 22UH 3A 70 MOHM TH	23092
B82432T1224K000 TDK EPCOS	FIXED IND 220UH 130MA 7.5 OHM	5533
B82442T1682K000 TDK EPCOS	FIXED IND 6.8UH 1.68A 106 MOHM	0
B82141A1105J000 TDK EPCOS	FIXED IND 1MH 55MA 33 OHM TH	929
B78148S1154J000 TDK EPCOS	FIXED IND 150UH 280MA 2.8 OHM TH	0
B82482M1822M000 TDK EPCOS	PCM120T-8R2M-D; 12.4X13.1X11.5 M	0
B82144A2335J000 TDK EPCOS	FIXED IND 3.3MH 110MA 12 OHM 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