Fixed Inductors

Part Number	Description / PDF	Quantity
B82462A4222M000 TDK EPCOS	FIXED IND 2.2UH 2.3A 42 MOHM SMD	3462
B82498F3470J001 TDK EPCOS	FIXED IND 47NH 600MA 130 MOHM	0
B82559A7103A016 TDK EPCOS	FIXED IND 10UH 11A 7.9 MOHM SMD	4365
B82144F2102K000 TDK EPCOS	FIXED IND 1UH 4.45A 43 MOHM TH	2652
B82472P6474M000 TDK EPCOS	FIXED IND 470UH 290MA 2 OHM SMD	2959
B82422T1122K000 TDK EPCOS	FIXED IND 1.2UH 390MA 700 MOHM	0
B82144F2104J000 TDK EPCOS	FIXED IND 100UH 1.3A 460 MOHM TH	1733
B82442T1106J000 TDK EPCOS	FIXED IND 10MH 46MA 112 OHM SMD	0
B82477P4333M000 TDK EPCOS	FIXED IND 33UH 3.35A 52 MOHM SMD	363
B78148E1223K000 TDK EPCOS	FIXED IND 22UH 1.3A 350 MOHM TH	193
B82422T1182J000 TDK EPCOS	FIXED IND 1.8UH 350MA 800 MOHM	0
B82422T1393J000 TDK EPCOS	FIXED IND 39UH 65MA 6.4 OHM SMD	0
B78108S1822K009 TDK EPCOS	FIXED IND 8.2UH 690MA 480 MOHM	0
B82422A3390K100 TDK EPCOS	FIXED IND 39NH 530MA 180 MOHM	0
B78108S1475J009 TDK EPCOS	FIXED IND 4.7MH 55MA 78 OHM TH	0
B82442T1474K000 TDK EPCOS	FIXED IND 470UH 240MA 4.73 OHM	0
B82479A1222M000 TDK EPCOS	FIXED IND 2.2UH 7.1A 14 MOHM SMD	0
B82442H1102K000 TDK EPCOS	FIXED IND 1UH 2.5A 24 MOHM SMD	398
B82422T3180K000 TDK EPCOS	FIXED IND 18NH 450MA 140 MOHM	0
B82144A2222K000 TDK EPCOS	FIXED IND 2.2UH 1.9A 110 MOHM TH	2885

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