Fixed Inductors

Part Number	Description / PDF	Quantity
MLK1005S18NJT000 TDK Corporation	FIXED IND 18NH 250MA 600 MOHM	17406
SLF6025T-470MR48-PF TDK Corporation	FIXED IND 47UH 670MA 288 MOHM	1894
MLG0603P1N0CTD25 TDK Corporation	FIXED IND 1NH 1A 70 MOHM SMD	13870
MHQ1005P5N6CT000 TDK Corporation	FIXED IND 5.6NH 800MA 130 MOHM	6357
VLS3010ET-220M TDK Corporation	FIXED IND 22UH 380MA 900 MOHM	293
VLF3012ST-150MR49 TDK Corporation	FIXED IND 15UH 490MA 490 MOHM	152
NLV32T-331J-PF TDK Corporation	FIXED IND 330UH 40MA 34 OHM SMD	11122
MLG0402Q1N5BT000 TDK Corporation	FIXED IND 1.5NH 220MA 600 MOHM	0
MLG1005S7N5JTD25 TDK Corporation	FIXED IND 7.5NH 500MA 250 MOHM	3787
MLG0603P3N9CTD25 TDK Corporation	FIXED IND 3.9NH 400MA 300 MOHM	14315
LGJ7045TC-331M-H TDK Corporation	FIXED IND 330UH 420MA 1.03 OHM	0
NLV32T-015J-PF TDK Corporation	FIXED IND 15NH 450MA 160 MOHM	0
MLG0603S9N1JT000 TDK Corporation	FIXED IND 9.1NH 200MA 800 MOHM	0
NLV32T-039J-EF TDK Corporation	FIXED IND 39NH 450MA 270 MOHM	652
MLP2520VR47MT TDK Corporation	FIXED IND 470NH 1.5A 78 MOHM SMD	0
MHQ0402PSA3N3CT000 TDK Corporation	FIXED IND 3.3NH 250MA 650 MOHM	0
NLV25T-018J-EF TDK Corporation	FIXED IND 18NH 450MA 310 MOHM	1703
VLS252012CX-1R0M TDK Corporation	FIXED IND 1UH 2.55A 62 MOHM SMD	0
VLS252010HBX-1R0M-1 TDK Corporation	FIXED IND 1UH 2.55A 65 MOHM SMD	25691
MHQ1005P18NJTD25 TDK Corporation	FIXED IND 18NH 260MA 800 MOHM	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