Fixed Inductors

Part Number	Description / PDF	Quantity
B82422T1121J000 TDK EPCOS	FIXED IND 120NH 450MA 150 MOHM	0
B82496C3399J000 TDK EPCOS	FIXED IND 3.9NH 1.1A 65 MOHM SMD	11073
B82422A1104J100 TDK EPCOS	FIXED IND 100UH 65MA 11.5 OHM	1797
B82559A4222A019 TDK EPCOS	FIXED IND 2.2UH 2.2 MOHM SMD	46
B82472G4153M000 TDK EPCOS	FIXED IND 15UH 1.4A 120 MOHM SMD	0
B82562N4102N000 TDK EPCOS	FIXED IND 1UH 4.8A 11 MOHM SMD	2990
B82144B1224J000 TDK EPCOS	FIXED IND 220UH 550MA 1.3 OHM TH	0
B82559B3222A027 TDK EPCOS	FIXED IND 2.2UH 46.5A 0.68 MOHM	210
B82498F3181J001 TDK EPCOS	FIXED IND 180NH 340MA 530 MOHM	962
B82422T1181J008 TDK EPCOS	FIXED IND 180NH 450MA 190 MOHM	0
B82464G4154M000 TDK EPCOS	FIXED IND 150UH 850MA 320 MOHM	975
B82472G6474M000 TDK EPCOS	FIXED IND 470UH 290MA 2 OHM SMD	969
B82442T1275J000 TDK EPCOS	FIXED IND 2.7MH 90MA 29.5 OHM	0
B82442T1152M050 TDK EPCOS	FIXED IND 1.5UH 3.02A 33 MOHM	1500
B82472G4683M000 TDK EPCOS	FIXED IND 68UH 690MA 460 MOHM	2178
B82422T1123J000 TDK EPCOS	FIXED IND 12UH 140MA 2.5 OHM SMD	0
B78148S1223K000 TDK EPCOS	FIXED IND 22UH 560MA 740 MOHM TH	0
B82477R4821M100 TDK EPCOS	FIXED IND 820NH 11.5A 5 MOHM SMD	0
B82559A5332A019 TDK EPCOS	FIXED IND 3.3UH 2.7 MOHM SMD	104
B82442T1106J50 TDK EPCOS	FIXED IND 10MH 46MA 112 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