Fixed Inductors

Part Number	Description / PDF	Quantity
B82477G4104M000 TDK EPCOS	FIXED IND 100UH 1.7A 165 MOHM	339
B82442H1684K000 TDK EPCOS	FIXED IND 680UH 140MA 8 OHM SMD	0
B78148E1222K000 TDK EPCOS	FIXED IND 2.2UH 3.4A 57 MOHM TH	4443
B82477P4392M000 TDK EPCOS	FIXED IND 3.9UH 8A 10 MOHM SMD	210
B82496C3270J000 TDK EPCOS	FIXED IND 27NH 360MA 550 MOHM	11276
B82562N4103M000 TDK EPCOS	FIXED IND 10UH 2.6A 35 MOHM SMD	0
B82498F3560G000 TDK EPCOS	FIXED IND 56NH 600MA 140 MOHM	0
B82559A6792A025 TDK EPCOS	FIXED INDUCTOR 7.9UH 2 MOHM SMD	95
B82442T1106K000 TDK EPCOS	FIXED IND 10MH 46MA 112 OHM SMD	0
B82432C1332K000 TDK EPCOS	FIXED IND 3.3UH 425MA 550 MOHM	0
B82442A1684K000 TDK EPCOS	FIXED IND 680UH 100MA 8 OHM SMD	0
B78108S1155J000 TDK EPCOS	FIXED IND 1.5MH 100MA 23 OHM TH	282
B82442A1153K000 TDK EPCOS	FIXED IND 15UH 580MA 240 MOHM	0
B82422T1152K000 TDK EPCOS	FIXED IND 1.5UH 370MA 700 MOHM	6082
B82442H1103K000 TDK EPCOS	FIXED IND 10UH 1A 168 MOHM SMD	5528
B82479A1684M000 TDK EPCOS	FIXED IND 680UH 720MA 1.2 OHM	0
B82464G4682M000 TDK EPCOS	FIXED IND 6.8UH 4.3A 20 MOHM SMD	3871
B82464A4153K000 TDK EPCOS	FIXED IND 15UH 2.5A 46 MOHM SMD	1362
B82422T1823K000 TDK EPCOS	FIXED IND 82UH 60MA 10 OHM SMD	0
B82144B2154J000 TDK EPCOS	FIXED IND 150UH 1.05A 700 MOHM	20

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