Fixed Inductors

Part Number	Description / PDF	Quantity
B82422T1471K000 TDK EPCOS	FIXED IND 470NH 450MA 300 MOHM	125
B82141A1222K009 TDK EPCOS	FIXED IND 2.2UH 630MA 250 MOHM	0
B82442H1393J000 TDK EPCOS	FIXED IND 39UH 520MA 580 MOHM	0
B82432C1474K000 TDK EPCOS	FIXED IND 470UH 75MA 17.5 OHM	2459
B82144B2123K000 TDK EPCOS	FIXED IND 12UH 2.4A 130 MOHM TH	993
B82144B2563J000 TDK EPCOS	FIXED IND 56UH 1.6A 310 MOHM TH	2929
B82422T1472J000 TDK EPCOS	FIXED IND 4.7UH 220MA 1.5 OHM	0
B82559A5332A020 TDK EPCOS	FIXED IND 3.3UH 1.5 MOHM SMD	133
B82498F3569K000 TDK EPCOS	FIXED IND 5.6NH 900MA 40 MOHM	0
B82464G4224M000 TDK EPCOS	FIXED IND 220UH 700MA 440 MOHM	831
B82442H1274K000 TDK EPCOS	FIXED IND 270UH 220MA 3.36 OHM	0
B82422A1223J100 TDK EPCOS	FIXED IND 22UH 140MA 2.65 OHM	2951
B78108E1683J009 TDK EPCOS	FIXED IND 68UH 780MA 900 MOHM TH	0
B82432C1274K000 TDK EPCOS	FIXED IND 270UH 90MA 12.5 OHM	0
B82472G6333M000 TDK EPCOS	FIXED IND 33UH 1.15A 150 MOHM	1812
B78148S1103K009 TDK EPCOS	FIXED IND 10UH 680MA 490 MOHM TH	0
B82498F3681G000 TDK EPCOS	FIXED IND 680NH 190MA 1.7 OHM	0
B82422T1272K000 TDK EPCOS	FIXED IND 2.7UH 290MA 900 MOHM	0
B82442A1105K000 TDK EPCOS	FIXED IND 1MH 85MA 12 OHM SMD	0
B82422T1122J000 TDK EPCOS	FIXED IND 1.2UH 390MA 700 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