Fixed Inductors

Part Number	Description / PDF	Quantity
SPM5015T-R47M-CA TDK Corporation	FIXED IND 470NH 7A 17.9 MOHM SMD	0
VLCF5020T-470MR40 TDK Corporation	FIXED IND 47UH 400MA 748 MOHM	617
VLF504012MT-1R0N-CA TDK Corporation	FIXED IND 1UH 3.19A 38 MOHM SMD	1975
MLK1005S3N3ST000 TDK Corporation	FIXED IND 3.3NH 400MA 220 MOHM	26314
VLS6045EX-330M-H TDK Corporation	FIXED IND 33UH 6045 SMD	7547
LGJ12575TS-1R2N8R2-H TDK Corporation	FIXED IND 1.2UH 8.2A 5.1 MOHM	420
VLF252010MT-3R3M TDK Corporation	FIXED IND 3.3UH 1.15A 190 MOHM	0
MLF2012DR68MT000 TDK Corporation	FIXED IND 680NH 150MA 600 MOHM	3871
MLG0603SR16JTD25 TDK Corporation	FIXED IND 160NH 50MA 8.3 OHM SMD	14900
NLCV32T-150K-PF TDK Corporation	FIXED IND 15UH 370MA 728 MOHM	12203
MLZ1005MR47WT000 TDK Corporation	FIXED IND 470NH 500MA 200 MOHM	16120
RLF7030T-1R0N6R4 TDK Corporation	FIXED IND 1UH 6.4A 8.76 MOHM SMD	193
VLF302515MT-1R5N TDK Corporation	FIXED IND 1.5UH 3.14A 38 MOHM	423
SPM10054T-150M-HZ TDK Corporation	FIXED IND 15UH 8.6A 33.93 MOHM	821
LTF5022T-470MR66-D TDK Corporation	FIXED IND 47UH 710MA 700 MOHM	791
VLS4012HBX-2R2M TDK Corporation	FIXED IND 2.2UH 3.72A 94MOHM SMD	3765
MLF2012DR39MT TDK Corporation	FIXED IND 390NH 200MA 450 MOHM	0
MHQ1005PR15JTD25 TDK Corporation	FIXED IND 150NH 110MA 3 OHM SMD	0
MLF2012DR82KT TDK Corporation	FIXED IND 820NH 150MA 650 MOHM	0
MLG0603S1N5CTD25 TDK Corporation	FIXED IND 1.5NH 550MA 150 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