Fixed Inductors

Part Number	Description / PDF	Quantity
B82476A1105M000 TDK EPCOS	FIXED IND 1MH 300MA 2.15 OHM SMD	635
B82442T1184K000 TDK EPCOS	FIXED IND 180UH 350MA 1.96 OHM	0
B82442H1395K000 TDK EPCOS	FIXED IND 3.9MH 53MA 56 OHM SMD	0
B82144A2685J000 TDK EPCOS	FIXED IND 6.8MH 80MA 30 OHM TH	0
B82422A1683K100 TDK EPCOS	FIXED IND 68UH 80MA 7.7 OHM SMD	6171
B82498F3150J000 TDK EPCOS	FIXED IND 15NH 650MA 130 MOHM	1491
B82144A2104J009 TDK EPCOS	FIXED IND 100UH 600MA 700 MOHM	0
B82442T1563K000 TDK EPCOS	FIXED IND 56UH 600MA 679 MOHM	0
B82498F3829K000 TDK EPCOS	FIXED IND 8.2NH 700MA 90 MOHM	2564
B82442A1474K000 TDK EPCOS	FIXED IND 470UH 120MA 5.6 OHM	1790
B82498F3270G000 TDK EPCOS	FIXED IND 27NH 700MA 90 MOHM SMD	0
B82442A1335J000 TDK EPCOS	FIXED IND 3.3MH 40MA 48 OHM SMD	0
B82477G4823M000 TDK EPCOS	FIXED IND 82UH 1.9A 145 MOHM SMD	434
B82442A1822K000 TDK EPCOS	FIXED IND 8.2UH 750MA 144 MOHM	980
B82477G2332M000 TDK EPCOS	FIXED IND 3.3UH 6A 17 MOHM SMD	0
B82141A1684J000 TDK EPCOS	FIXED IND 680UH 65MA 22 OHM TH	0
B82464A4152M000 TDK EPCOS	FIXED IND 1.5UH 6.5A 10 MOHM SMD	0
B82442T1472K000 TDK EPCOS	FIXED IND 4.7UH 1.95A 73 MOHM	0
B82422T3270J000 TDK EPCOS	FIXED IND 27NH 450MA 170 MOHM	0
B82442H1106K000 TDK EPCOS	FIXED IND 10MH 35MA 120 OHM SMD	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