Fixed Inductors

Part Number	Description / PDF	Quantity
B82422T3100K000 TDK EPCOS	FIXED IND 10NH 450MA 100 MOHM	7726
B82473A1104K000 TDK EPCOS	FIXED IND 100UH 720MA 430 MOHM	390
B78108E1333J000 TDK EPCOS	FIXED IND 33UH 1.05A 550 MOHM TH	3899
B82442H1105J000 TDK EPCOS	FIXED IND 1MH 120MA 12 OHM SMD	4142
B82432T1154K000 TDK EPCOS	FIXED IND 150UH 160MA 6 OHM SMD	0
B82442H1275J000 TDK EPCOS	FIXED IND 2.7MH 65MA 44 OHM SMD	0
B82144A2106J000 TDK EPCOS	FIXED IND 10MH 60MA 42 OHM TH	546
B82422A1272K100 TDK EPCOS	FIXED IND 2.7UH 240MA 880 MOHM	67
B82442T1183K000 TDK EPCOS	FIXED IND 18UH 1.09A 210 MOHM	0
B82498F3689K000 TDK EPCOS	FIXED IND 6.8NH 800MA 50 MOHM	4249
B82144B1104J000 TDK EPCOS	FIXED IND 100UH 760MA 700 MOHM	0
B82498F3101G001 TDK EPCOS	FIXED IND 100NH 450MA 280 MOHM	0
B82422T1562J000 TDK EPCOS	FIXED IND 5.6UH 200MA 1.6 OHM	0
B78108E1223K009 TDK EPCOS	FIXED IND 22UH 1.3A 350 MOHM TH	1
B82498F3680G001 TDK EPCOS	FIXED IND 68NH 500MA 180 MOHM	0
B82442A1182K000 TDK EPCOS	FIXED IND 1.8UH 1.4A 40 MOHM SMD	0
B78148E1332K009 TDK EPCOS	FIXED IND 3.3UH 3.05A 73 MOHM TH	0
B82144A2155J009 TDK EPCOS	FIXED IND 1.5MH 160MA 6 OHM TH	0
B82144F2184J000 TDK EPCOS	FIXED IND 180UH 950MA 785 MOHM	2517
B82477D4104M900 TDK EPCOS	FIXED IND 100UH 1.61A 280 MOHM	350

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