Fixed Inductors

Part Number	Description / PDF	Quantity
FIT44-3 Triad Magnetics	FIXED IND 12.3UH 4A 23.4 MOHM TH	178
AX97-30221 Triad Magnetics	FIXED IND 220UH 1A 640 MOHM SMD	700
FIT50-1 Triad Magnetics	FIXED IND 47.4UH 2.8A 78.9 MOHM	582
AX97-30101 Triad Magnetics	FIXED IND 100UH 1.5A 300 MOHM	350
AX02-303R9 Triad Magnetics	FIXED IND 3.9UH 10A 6.8 MOHM SMD	0
FIT80-3 Triad Magnetics	FIXED IND 80.75UH 5.7A 44.8 MOHM	126
AX97-301R5 Triad Magnetics	FIXED IND 1.5UH 7.9A 10 MOHM SMD	0
AX97-406R8 Triad Magnetics	FIXED IND 6.8UH 7.7A 20 MOHM SMD	0
AX97-40470 Triad Magnetics	FIXED IND 47UH 3A 70 MOHM SMD	0
FIT80-3-B Triad Magnetics	FIXED IND 80.75UH 5.7A 44.8 MOHM	432
AX104R-8R2 Triad Magnetics	FIXED IND 8.2UH 4.6A 25 MOHM SMD	0
AX97-30151 Triad Magnetics	FIXED IND 150UH 1.2A 440 MOHM	0
RC-5-B Triad Magnetics	FIXED IND 915UH 625MA 1 OHM TH	0
RC-9-B Triad Magnetics	FIXED IND 200UH 1.6A 180 MOHM TH	0
RC-4 Triad Magnetics	FIXED IND 1.5MH 500MA 1.53 OHM	272
RC-11-B Triad Magnetics	FIXED IND 75UH 2.5A 70 MOHM TH	0
FIT50-3 Triad Magnetics	FIXED IND 27.16UH 4A 40.1 MOHM	0
AX97-10151 Triad Magnetics	FIXED IND 150UH 220MA 3.08 OHM	0
FIT106-3-B Triad Magnetics	FIXED IND 154UH 5.7A 74 MOHM TH	0
FIT68-5 Triad Magnetics	FIXED IND 33.15UH 5.7A 28.8 MOHM	5641

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