Fixed Inductors

Part Number	Description / PDF	Quantity
MHQ1005P2N6CT000 TDK Corporation	FIXED IND 2.6NH 900MA 70 MOHM	0
MHQ1005P2N7CTD25 TDK Corporation	FIXED IND 2.7NH 900MA 70 MOHM	0
TFM252012ALMA1R0MTAA TDK Corporation	FIXED IND 1UH 3.7A 42 MOHM SMD	62856
VLS3015CX-220M-H TDK Corporation	INDUCTORS FOR POWER CIRCUITS, AU	3767
MLK1005S68NJTD25 TDK Corporation	FIXED IND 68NH 150MA 1.5 OHM SMD	17398
SLF12575T-470M2R7-H TDK Corporation	FIXED IND 47UH 2.7A 63.36 MOHM	777
VLF403210MT-6R8M-CA TDK Corporation	FIXED IND 6.8UH 1.24A 220 MOHM	0
MHQ1005P5N1CT000 TDK Corporation	FIXED IND 5.1NH 800MA 120 MOHM	0
NLCV32T-R68M-PFR TDK Corporation	FIXED IND 680NH 1.9A 54 MOHM SMD	1210
MLG0603P1N7BT000 TDK Corporation	FIXED IND 1.7NH 700MA 100 MOHM	0
MLG0402P12NJT000 TDK Corporation	FIXED IND 12NH 140MA 2.4 OHM SMD	0
SPM3020T-R47M-CA TDK Corporation	FIXED IND 470NH 4.8A 28.9 MOHM	0
MLJ1608WR22JT000 TDK Corporation	FIXED IND 220NH 600MA 260 MOHM	13606
MHQ0603P4N2BTD25 TDK Corporation	FIXED IND 4.2NH 400MA 350 MOHM	4054
SPM10040T-3R3M-HZ TDK Corporation	FIXED IND 3.3UH 15.3A 11MOHM SMD	971
VLF302515MT-150M TDK Corporation	FIXED IND 15UH 990MA 330 MOHM	0
MHQ0402PSA0N4ST000 TDK Corporation	FIXED IND 0.4NH 600MA 150 MOHM	0
CLF7045T-220M-D TDK Corporation	FIXED IND 22UH 1.8A 82.8 MOHM	702
MLG0402Q2N0ST000 TDK Corporation	FIXED IND 2NH 200MA 600 MOHM SMD	13649
NLV25T-047J-PFD TDK Corporation	FIXED IND 47NH 360MA 500 MOHM	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