Fixed Inductors

Part Number	Description / PDF	Quantity
MLF1608DR39MTD25 TDK Corporation	FIXED IND 390NH 100MA 850 MOHM	0
VLS201610HBX-3R3M-1 TDK Corporation	FIXED IND 3.3UH 1.2A 252 MOHM	1266
VLS252010CX-6R8M-1 TDK Corporation	FIXED IND 6.8UH 860MA 372 MOHM	3710
SPM6550CT-R50L TDK Corporation	FIXED IND 500NH 13.2A 4.29 MOHM	1828
VLB10090HT-R10M-GT TDK Corporation	FIXED IND 100NH 60A 0.33 MOHM	600
VLF504010MT-2R2M-CA TDK Corporation	FIXED IND 2.2UH 2.65A 54 MOHM	0
CLF5030NIT-330M-D TDK Corporation	FIXED IND 33UH 880MA 372 MOHM	2208
MLG0603P1N9BT000 TDK Corporation	FIXED IND 1.9NH 600MA 100 MOHM	0
VLF10040T-4R7N5R4 TDK Corporation	FIXED IND 4.7UH 5.4A 15.3 MOHM	0
MLG0603P91NJT000 TDK Corporation	FIXED IND 91NH 80MA 4.5 OHM SMD	9191
SPM5012T-2R2M TDK Corporation	FIXED IND 2.2UH 2.7A 78.8 MOHM	30
MLG0402P2N7ST000 TDK Corporation	FIXED IND 2.7NH 200MA 800 MOHM	0
MLF1005G2R2KT TDK Corporation	FIXED IND 2.2UH 30MA 1.3 OHM SMD	0
SLF10145T-102MR29-PF TDK Corporation	FIXED IND 1MH 290MA 3.36 OHM SMD	6772
VLF252015MT-1R5N-CA TDK Corporation	FIXED IND 1.5UH 2.58A 39 MOHM	1688
CLF10040T-331M-D TDK Corporation	FIXED IND 330UH 530MA 1.032 OHM	81
VLF504010MT-1R0N TDK Corporation	FIXED IND 1UH 3.08A 37 MOHM SMD	267
SPM10054T-330M-HZ TDK Corporation	FIXED IND 33UH 5.3A 82.13 MOHM	828
MLG0402Q12NJT000 TDK Corporation	FIXED IND 12NH 140MA 2.4 OHM SMD	13178
NLV32T-R47J-EF TDK Corporation	FIXED IND 470NH 450MA 500 MOHM	315

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