Fixed Inductors

Part Number	Description / PDF	Quantity
B82442A1394J000 TDK EPCOS	FIXED IND 390UH 130MA 4.64 OHM	0
B82422A1103J108 TDK EPCOS	FIXED IND 10UH 180MA 1.6 OHM SMD	0
B82442H1106J000 TDK EPCOS	FIXED IND 10MH 35MA 120 OHM SMD	0
B82464P4334M000 TDK EPCOS	FIXED IND 330UH 590MA 650 MOHM	513
B82464A4333K000 TDK EPCOS	FIXED IND 33UH 1.8A 100 MOHM SMD	545
B82432T1823K000 TDK EPCOS	FIXED IND 82UH 220MA 3 OHM SMD	0
B82442T1273K000 TDK EPCOS	FIXED IND 27UH 880MA 307 MOHM	0
B78108S1334J009 TDK EPCOS	FIXED IND 330UH 190MA 6.4 OHM TH	0
B82498F3569K001 TDK EPCOS	FIXED IND 5.6NH 900MA 40 MOHM	2948
B82422A1563K100 TDK EPCOS	FIXED IND 56UH 85MA 6.75 OHM SMD	1508
B82144B2102K000 TDK EPCOS	FIXED IND 1UH 4.45A 43 MOHM TH	572
B82498F3330G001 TDK EPCOS	FIXED IND 33NH 600MA 110 MOHM	0
B82141A1682K009 TDK EPCOS	FIXED IND 6.8UH 480MA 430 MOHM	0
B82498F3271J000 TDK EPCOS	FIXED IND 270NH 270MA 1 OHM SMD	0
B82462A4223K000 TDK EPCOS	FIXED IND 22UH 800MA 260 MOHM	2498
B82442T1185J000 TDK EPCOS	FIXED IND 1.8MH 110MA 19.7 OHM	0
B82464P4224M000 TDK EPCOS	FIXED IND 220UH 700MA 440 MOHM	255
B82498F3390G000 TDK EPCOS	FIXED IND 39NH 600MA 120 MOHM	0
B82422A3820K100 TDK EPCOS	FIXED IND 82NH 450MA 240 MOHM	0
B82422T1822J000 TDK EPCOS	FIXED IND 8.2UH 170MA 2 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