Fixed Inductors

Part Number	Description / PDF	Quantity
B82464A4223K000 TDK EPCOS	FIXED IND 22UH 2.1A 85 MOHM SMD	1923
B82476A1472M000 TDK EPCOS	FIXED IND 4.7UH 4.8A 16.5 MOHM	672
B78108S1392K000 TDK EPCOS	FIXED IND 3.9UH 850MA 310 MOHM	0
B82442H1335K000 TDK EPCOS	FIXED IND 3.3MH 55MA 48 OHM SMD	31
B82496C3680G000 TDK EPCOS	FIXED IND 68NH 230MA 1.3 OHM SMD	0
B82144F2682K000 TDK EPCOS	FIXED IND 6.8UH 2.75A 95 MOHM TH	1735
B82442A1392K000 TDK EPCOS	FIXED IND 3.9UH 1.05A 72 MOHM	0
B82422T3470J000 TDK EPCOS	FIXED IND 47NH 450MA 200 MOHM	0
B82477G4474M000 TDK EPCOS	FIXED IND 470UH 800MA 790 MOHM	929
B82442T1184K050 TDK EPCOS	FIXED IND 180UH 350MA 1.96 OHM	0
B82144A2682K000 TDK EPCOS	FIXED IND 6.8UH 1.5A 190 MOHM TH	0
B82498F1182J000 TDK EPCOS	FIXED IND 1.8UH 190MA 980 MOHM	0
B82432T1473K000 TDK EPCOS	FIXED IND 47UH 350MA 1.35 OHM	8252
B82462G4224M000 TDK EPCOS	FIXED IND 220UH 350MA 1.35 OHM	8306
B82144F2334J000 TDK EPCOS	FIXED IND 330UH 700MA 1.53 OHM	681
B82422T1822K000 TDK EPCOS	FIXED IND 8.2UH 170MA 2 OHM SMD	0
B82500C0000A005 TDK EPCOS	FIXED IND 820UH 500MA 2.5 OHM TH	173
B82432T1474K000 TDK EPCOS	FIXED IND 470UH 100MA 15 OHM SMD	7592
B82442A1682K000 TDK EPCOS	FIXED IND 6.8UH 810MA 120 MOHM	490
B82442A1105J000 TDK EPCOS	FIXED IND 1MH 85MA 12 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