Fixed Inductors

Part Number	Description / PDF	Quantity
0402DC-3N3XJRW COILCRAFT	CERAMIC CHIP INDUCTORS, 3.3NH	5696
0603DC-4N3XGRW COILCRAFT	CERAMIC CHIP INDUCTORS 4.3NH	877
LPS4018-684MRC COILCRAFT	SHIELDED POWER INDUCTORS, 680UH	1236
0603DC-91NXJRW COILCRAFT	CERAMIC CHIP INDUCTORS 91NH	4397
0603AF-72NXJEW COILCRAFT	WIREWOUND INDUCTOR 72NH@7.9MHZ	1322
0402DC-8N1XGRW COILCRAFT	CERAMIC CHIP INDUCTORS, 8.1NH	1864
XGL4020-472MEC COILCRAFT	SHIELDED POWER INDUCTORS, 4.7UH	0
XGL4020-601MEC COILCRAFT	SHIELDED POWER INDUCTORS, 0.60UH	4190
XGL4030-472MEC COILCRAFT	SHIELDED POWER INDUCTORS, 4.7UH	0
LPS4018-103MRC COILCRAFT	SHIELDED POWER INDUCTORS, 10UH	0
0402DC-N90XKRW COILCRAFT	CERAMIC CHIP INDUCTORS, 0.9NH	0
XGL4030-131MEC COILCRAFT	SHIELDED POWER INDUCTORS, 0.13UH	707
0603DC-33NXGRW COILCRAFT	CERAMIC CHIP INDUCTORS 33NH	3994
0402DC-91NXJRW COILCRAFT	CERAMIC CHIP INDUCTORS, 91.0NH	7554
0402DC-4N7XJRW COILCRAFT	CERAMIC CHIP INDUCTORS, 4.7NH	590
LPS4018-683MRC COILCRAFT	SHIELDED POWER INDUCTORS, 68UH	0
LPS4018-332MRC COILCRAFT	SHIELDED POWER INDUCTORS, 3.3UH	211529
0603DC-16NXGRW COILCRAFT	CERAMIC CHIP INDUCTOR,16NH	4154
0402DC-72NXJRW COILCRAFT	CERAMIC CHIP INDUCTORS, 72.0NH	8888
0402DC-3N6XGRW COILCRAFT	CERAMIC CHIP INDUCTORS, 3.6NH	2634

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