Fixed Inductors

Part Number	Description / PDF	Quantity
B82432T1122K000 TDK EPCOS	FIXED IND 1.2UH 1.2A 100 MOHM	0
B82476B1223M100 TDK EPCOS	FIXED IND 22UH 2.95A 50 MOHM SMD	117
B82477D4333M900 TDK EPCOS	FIXED IND 33UH 2.68A 110 MOHM	350
B82141A1222K000 TDK EPCOS	FIXED IND 2.2UH 630MA 250 MOHM	2109
B82442A1273K000 TDK EPCOS	FIXED IND 27UH 440MA 420 MOHM	0
B82496C3100J000 TDK EPCOS	FIXED IND 10NH 600MA 200 MOHM	6819
B82464G4332M000 TDK EPCOS	FIXED IND 3.3UH 5.5A 12 MOHM SMD	1076
B82422T3390K000 TDK EPCOS	FIXED IND 39NH 450MA 190 MOHM	0
B82442T1473K000 TDK EPCOS	FIXED IND 47UH 700MA 519 MOHM	0
B82473M1474K000 TDK EPCOS	FIXED IND 470UH 340MA 1.96 OHM	0
B78148S1472K000 TDK EPCOS	FIXED IND 4.7UH 820MA 340 MOHM	0
B82442T1104K050 TDK EPCOS	FIXED IND 100UH 510MA 990 MOHM	2556
B82477G2103M000 TDK EPCOS	FIXED IND 10UH 4A 25 MOHM SMD	854
B78148E1333J000 TDK EPCOS	FIXED IND 33UH 1.05A 550 MOHM TH	591
B82559B6682A016 TDK EPCOS	FIXED IND 6.8UH 14.4A 6.2 MOHM	560
B82477R4683M100 TDK EPCOS	FIXED IND 68UH 2.8A 85 MOHM SMD	229
B82442H1565K000 TDK EPCOS	FIXED IND 5.6MH 46MA 68 OHM SMD	0
B82141A1124J000 TDK EPCOS	FIXED IND 120UH 160MA 3.8 OHM TH	0
B82422A3150K108 TDK EPCOS	FIXED IND 15NH 640MA 120 MOHM	0
B78108S1682K009 TDK EPCOS	FIXED IND 6.8UH 670MA 510 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