Fixed Inductors

Part Number	Description / PDF	Quantity
MLG0603P3N9STD25 TDK Corporation	FIXED IND 3.9NH 400MA 300 MOHM	0
MHQ1005P10NGTD25 TDK Corporation	FIXED IND 10NH 500MA 190 MOHM	0
MLG0402Q3N0ST000 TDK Corporation	FIXED IND 3NH 200MA 800 MOHM SMD	0
MLG0402Q18NHT000 TDK Corporation	FIXED IND 18NH 140MA 2.8 OHM SMD	0
CLF10040T-220M-D TDK Corporation	FIXED IND 22UH 2.2A 55 MOHM SMD	5628
MLG0603S56NJT000 TDK Corporation	FIXED IND 56NH 50MA 3.2 OHM SMD	8936
LTF5022T-4R7N2R0-D TDK Corporation	FIXED IND 4.7UH 2.18A 74 MOHM	34
VLS2012ET-150M-CA TDK Corporation	FIXED IND 15UH 470MA 1.062 OHM	1897
NLV25T-100J-EFD TDK Corporation	FIXED IND 10UH 155MA 3.5 OHM SMD	597
MLF1005GR82JT TDK Corporation	FIXED IND 820NH 40MA 590 MOHM	0
VLF504012MT-1R0N TDK Corporation	FIXED IND 1UH 3.19A 38 MOHM SMD	2000
MLG0603PPA2N7CT000 TDK Corporation	FIXED IND 2.7NH 1.3A 65 MOHM	24797
NLFV25T-101K-PF TDK Corporation	FIXED IND 100UH 40MA 4.8 OHM SMD	110
VLCF4020T-3R3N1R5 TDK Corporation	FIXED IND 3.3UH 1.52A 78 MOHM	10237
MLG0402Q4N7ST000 TDK Corporation	FIXED IND 4.7NH 160MA 1.3 OHM	33060
MHQ1005PR11JT000 TDK Corporation	FIXED IND 110NH 150MA 2.7 OHM	0
VLF403212MT-4R7M-CA TDK Corporation	FIXED IND 4.7UH 1.85A 120 MOHM	0
MHQ1005P5N6ST000 TDK Corporation	FIXED IND 5.6NH 800MA 130 MOHM	15429
CLF12555T-2R2N-H TDK Corporation	FIXED IND 2.2UH 6.1A 8.8 MOHM	500
LTF5022T-101MR45-LC TDK Corporation	FIXED IND 100UH 530MA 1.28 OHM	170

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