Fixed Inductors

Part Number	Description / PDF	Quantity
MLF2012C270MT TDK Corporation	FIXED IND 27UH 5MA 1 OHM SMD	0
MHQ1005P1N9CTD25 TDK Corporation	FIXED IND 1.9NH 1A 50 MOHM SMD	0
MHQ0603P1N2BTD25 TDK Corporation	FIXED IND 1.2NH 1A 80MOHM SMD	4116
CLF6045T-1R5N TDK Corporation	FIXED IND 1.5UH 4.2A 16.9 MOHM	113
SPM10065VT-1R5M-D TDK Corporation	FIXED IND 1.5UH 20.2A 3.1 MOHM	800
MHQ0603P5N6CT000 TDK Corporation	FIXED IND 5.6NH 350MA 400 MOHM	9010
VLS5045EX-6R8M TDK Corporation	FIXED IND 6.8UH 2.9A 59.8 MOHM	7893
MLG0603S1N8STD25 TDK Corporation	FIXED IND 1.8NH 500MA 200 MOHM	0
MLZ2012M4R7HTD25 TDK Corporation	FIXED IND 4.7UH 400MA 340 MOHM	0
MLG1608B1N8ST000 TDK Corporation	FIXED IND 1.8NH 600MA 100 MOHM	4029
SLF10145T-100M2R5-H TDK Corporation	FIXED IND 10UH 2.5A 36.4 MOHM	30660
SLF12565T-4R2N5R5-PF TDK Corporation	FIXED IND 4.2UH 5.5A 18 MOHM SMD	0
MLG0603S13NHT000 TDK Corporation	FIXED IND 13NH 180MA 900 MOHM	0
TFM322512ALMA100MTAA TDK Corporation	FIXED IND 10UH 1.2A 360 MOHM SMD	0
VLF3010ST-6R8MR65 TDK Corporation	FIXED IND 6.8UH 650MA 250 MOHM	958
MHQ0603P2N1CT000 TDK Corporation	FIXED IND 2.1NH 700MA 150 MOHM	0
MHQ0402PSA4N2CT000 TDK Corporation	FIXED IND 4.2NH 200MA 800 MOHM	0
NL453232T-1R2J-PF TDK Corporation	FIXED IND 1.2UH 430MA 550 MOHM	864
MHQ1005P12NGT000 TDK Corporation	FIXED IND 12NH 450MA 240 MOHM	9277
MLP2016V1R5MT0S1 TDK Corporation	FIXED IND 1.5UH 1.15A 175 MOHM	5415

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