Fixed Inductors

Part Number	Description / PDF	Quantity
0603DC-18NXGRW COILCRAFT	CERAMIC CHIP INDUCTOR,18NH	4563
0603DC-R22XJRW COILCRAFT	CERAMIC CHIP INDUCTOR,220NH	4426
0402DF-200XJRW COILCRAFT	WIREWOUND FERRITE BEAD 20NH	1058
0402DC-33NXJRW COILCRAFT	CERAMIC CHIP INDUCTORS, 33.0NH	10562
0402DF-151XJRW COILCRAFT	WIREWOUND FERRITE BEAD 150NH	1814
0402DC-3N6XJRW COILCRAFT	CERAMIC CHIP INDUCTORS, 3.6NH	8065
XGL4020-682MEC COILCRAFT	SHIELDED POWER INDUCTORS, 6.8UH	8670
0603DC-7N5XGRW COILCRAFT	CERAMIC CHIP INDUCTORS 7.5NH	4147
LPS4018-824MRC COILCRAFT	SHIELDED POWER INDUCTORS, 820UH	1663
0603AF-152XJEW COILCRAFT	WIREWOUND INDUCTOR 1500NH@7.9MHZ	6002
0402DF-421XJRW COILCRAFT	WIREWOUND FERRITE BEAD 420NH	2310
LPS3015-183MRC COILCRAFT	SHIELDED POWER INDUCTORS 18H	389
0402DF-102XJRW COILCRAFT	WIREWOUND FERRITE BEAD 1000NH	738
0402DC-5N7XGRW COILCRAFT	CERAMIC CHIP INDUCTORS, 5.7NH	1394
0402DC-3N7XGRW COILCRAFT	CERAMIC CHIP INDUCTORS, 3.7NH	1372
0402DC-4N2XGRW COILCRAFT	CERAMIC CHIP INDUCTORS, 4.2NH	2108
0402DF-531XJRW COILCRAFT	WIREWOUND FERRITE BEAD 530NH	948
0402DF-301XJRW COILCRAFT	WIREWOUND FERRITE BEAD 300NH	5557
0603AF-361XJEW COILCRAFT	WIREWOUND INDUCTOR 360NH@7.9MHZ	8142
0402DF-560XJRW COILCRAFT	WIREWOUND FERRITE BEAD 56NH	131

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