Fixed Inductors

Part Number	Description / PDF	Quantity
AX97-10680 Triad Magnetics	FIXED IND 68UH 370MA 1.39 OHM	0
RC-2-B Triad Magnetics	FIXED IND 3.9MH 320MA 3.9 OHM TH	0
AX97-20470 Triad Magnetics	FIXED IND 47UH 800MA 310 MOHM	0
AX104R-151 Triad Magnetics	FIXED IND 150UH 1.15A 506 MOHM	0
AX02-302R2 Triad Magnetics	FIXED IND 2.2UH 12A 5.1 MOHM SMD	0
FIT106-4 Triad Magnetics	FIXED IND 116UH 6.8A 48.5 MOHM	1161522
FIRCH-6 Triad Magnetics	FIXED IND 7.22UH 4.8A 26.1 MOHM	197
FIT80-4-B Triad Magnetics	FIXED IND 65.04UH 6.8A 32.8 MOHM	432
AX97-20681 Triad Magnetics	FIXED IND 680UH 100MA 3.5 OHM	0
FIRCH-1 Triad Magnetics	FIXED IND 2.54UH 11.6A 5.5 MOHM	15
AX97-30471 Triad Magnetics	FIXED IND 470UH 500MA 1.5 OHM	0
AX97-40151 Triad Magnetics	FIXED IND 150UH 1.7A 220 MOHM	0
AX104R-220 Triad Magnetics	FIXED IND 22UH 2.9A 73 MOHM SMD	0
AX97-30820 Triad Magnetics	FIXED IND 82UH 1.58A 240 MOHM	0
AX104R-221 Triad Magnetics	FIXED IND 220UH 920MA 756 MOHM	0
C-49U Triad Magnetics	FIXED IND 32MH 5A 28 MOHM CHASS	17111
AX97-302R2 Triad Magnetics	FIXED IND 2.2UH 7.4A 20 MOHM SMD	0
FIRCH-1-B Triad Magnetics	FIXED IND 2.54UH 11.6A 5.5 MOHM	462
AX97-10221 Triad Magnetics	FIXED IND 220UH 180MA 4.47 OHM	0
FIRCH-4 Triad Magnetics	FIXED IND 5UH 6.8A 14.1 MOHM TH	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