Fixed Inductors

Part Number	Description / PDF	Quantity
0402DC-1N9XJRW COILCRAFT	CERAMIC CHIP INDUCTORS, 1.9NH	3086
XGL4020-821MEC COILCRAFT	SHIELDED POWER INDUCTORS, 0.82UH	8265
0402DC-24NXGRW COILCRAFT	CERAMIC CHIP INDUCTORS, 24.0NH	1488
0402DC-51NXJRW COILCRAFT	CERAMIC CHIP INDUCTORS, 51.0NH	6950
0402DC-18NXGRW COILCRAFT	CERAMIC CHIP INDUCTORS, 18.0NH	7838
0402DC-7N4XGRW COILCRAFT	CERAMIC CHIP INDUCTORS, 7.4NH	18
0603DC-51NXGRW COILCRAFT	CERAMIC CHIP INDUCTORS 51NH	4130
0402DC-7N8XGRW COILCRAFT	CERAMIC CHIP INDUCTORS, 7.8NH	2307
0402DC-3N9XJRW COILCRAFT	CERAMIC CHIP INDUCTORS, 3.9NH	10398
0402DC-75NXGRW COILCRAFT	CERAMIC CHIP INDUCTORS, 75.0NH	1788
XGL4030-471MEC COILCRAFT	SHIELDED POWER INDUCTORS, 0.47UH	1632
0603DC-27NXGRW COILCRAFT	CERAMIC CHIP INDUCTORS 27NH	5120
0402DC-7N0XGRW COILCRAFT	CERAMIC CHIP INDUCTORS, 7.0NH	0
0402DC-5N6XGRW COILCRAFT	CERAMIC CHIP INDUCTORS, 5.6NH	13754
0603DC-82NXJRW COILCRAFT	CERAMIC CHIP INDUCTORS 82NH	4426
0402DC-1N2XJRW COILCRAFT	CERAMIC CHIP INDUCTORS, 1.2NH	1524
0603DC-36NXJRW COILCRAFT	CERAMIC CHIP INDUCTORS 36NH	4400
0402DC-R10XJRW COILCRAFT	CERAMIC CHIP INDUCTORS, 100NH	5563
0603DC-9N1XGRW COILCRAFT	CERAMIC CHIP INDUCTORS 9.1NH	3568
0603AF-821XJEW COILCRAFT	WIREWOUND INDUCTOR 820NH@7.9MHZ	3214

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