Fixed Inductors

Part Number	Description / PDF	Quantity
VLS252012CX-100M TDK Corporation	FIXED IND 10UH 820MA 482 MOHM	0
MLF2012C330KT000 TDK Corporation	FIXED IND 33UH 5MA 1.1 OHM SMD	6436
MLG0603P2N6CTD25 TDK Corporation	FIXED IND 2.6NH 500MA 200 MOHM	0
VLS252008ET-2R2M-CA TDK Corporation	FIXED IND 2.2UH 840MA 290 MOHM	3217
MLF1608DR33JT000 TDK Corporation	FIXED IND 330NH 100MA 750 MOHM	3730
TFM252012ALMAR68MTAA TDK Corporation	FIXED IND 680NH 4.1A 34 MOHM SMD	0
SPM4015T-R47M-CA TDK Corporation	FIXED IND 470NH 5.5A 24.4 MOHM	2126
VLCF5024T-330MR50-2 TDK Corporation	FIXED IND 33UH 500MA 275 MOHM	230
MLF2012E5R6KT000 TDK Corporation	FIXED IND 5.6UH 15MA 600 MOHM	422
MHQ0603P3N7CT000 TDK Corporation	FIXED IND 3.7NH 450MA 250 MOHM	0
MHQ1005P0N9BT000 TDK Corporation	FIXED IND 0.9NH 1.2A 30 MOHM SMD	7210
VLBU10060120T-R09L-1 TDK Corporation	FIXED IND 90NH 83A 0.12 MOHM SMD	560
MLG1608SR27JTD25 TDK Corporation	FIXED IND 270NH 200MA 2 OHM SMD	317
MLF2012A1R8KTD25 TDK Corporation	FIXED IND 1.8UH 80MA 450 MOHM	3717
VLS3012HBX-4R7M TDK Corporation	FIXED IND 4.7UH 2.23A 201 MOHM	32295
MLJ1005WR12JT000 TDK Corporation	FIXED IND 120NH 450MA 390 MOHM	19069
MLF1608A1R2MTD25 TDK Corporation	FIXED IND 1.2UH 50MA 650 MOHM	0
NLCV32T-330K-EF TDK Corporation	FIXED IND 33UH 240MA 1.43 OHM	25660
MHQ1005PR12GTD25 TDK Corporation	FIXED IND 120NH 140MA 2.7 OHM	0
LGJ7045TS-220M1R3-H TDK Corporation	FIXED IND 22UH 1.25A 82 MOHM SMD	1000

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