Fixed Inductors

Part Number	Description / PDF	Quantity
SPM3010T-4R7M-LR TDK Corporation	FIXED IND 4.7UH 1.4A 374.6 MOHM	3976
MLG0402Q3N5ST000 TDK Corporation	FIXED IND 3.5NH 180MA 1.1 OHM	0
NLV25T-R68J-PFD TDK Corporation	FIXED IND 680NH 300MA 850 MOHM	0
CLF6045T-150M-CA TDK Corporation	FIXED IND 15UH 2A 66 MOHM SMD	91
MHQ1005P0N7CTD25 TDK Corporation	FIXED IND 0.7NH 1.2A 30 MOHM SMD	0
MHQ0603P12NHTD25 TDK Corporation	FIXED IND 12NH 240MA 1.4OHM SMD	15000
MLG0603SR12JT000 TDK Corporation	FIXED IND 120NH 50MA 7 OHM SMD	0
NLV32T-820J-EF TDK Corporation	FIXED IND 82UH 45MA 10 OHM SMD	1645
MHQ1005P0N8BT000 TDK Corporation	FIXED IND 0.8NH 1.2A 30 MOHM SMD	19959
MLG0603P1N2BT000 TDK Corporation	FIXED IND 1.2NH 800MA 80 MOHM	0
SPM5030T-1R0M-HZ TDK Corporation	FIXED IND 1UH 10.4A 11.44 MOHM	62
VLS252008ET-100M TDK Corporation	FIXED IND 10UH 410MA 1.232 OHM	6199
GLFR1608T150M-LR TDK Corporation	FIXED IND 15UH 220MA 900 MOHM	3608
VLS252010CX-1R5M-1 TDK Corporation	FIXED IND 1.5UH 1.9A 86 MOHM SMD	0
VLBU805080T-R10L TDK Corporation	FIXED IND 100NH 65A 0.2 MOHM SMD	1791
MLJ1005WR47JT000 TDK Corporation	FIXED IND 470NH 300MA 970 MOHM	33950
LTF5022T-4R7N2R0-LC TDK Corporation	FIXED IND 4.7UH 2.3A 81 MOHM SMD	7552
MLG1005SR24HT000 TDK Corporation	FIXED IND 240NH 100MA 4.8 OHM	0
MHQ1005PR13GTD25 TDK Corporation	FIXED IND 130NH 110MA 2.9 OHM	0
MHQ1005PR15HTD25 TDK Corporation	FIXED IND 150NH 110MA 3 OHM SMD	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