Fixed Inductors

Part Number	Description / PDF	Quantity
74478215 Würth Elektronik Midcom	FIXED IND 15NH 250MA 1.4 OHM SMD	0
1537-88J API Delevan	FIXED IND 180UH 123MA 6.75 OHM	0
LQW18ASR10J00D TOKO / Murata	FIXED IND 100NH 400MA 580 MOHM	0
1025R-18K API Delevan	FIXED IND 820NH 420MA 850 MOHM	931
CLF10040T-471M-CA TDK Corporation	FIXED IND 470UH 440MA 1.452 OHM	505
3632B682LL TE Connectivity AMP Connectors	FIXED IND 6.8MH 100MA 16.5 OHM	0
VLF504010MT-3R3M-CA TDK Corporation	FIXED IND 3.3UH 2.1A 91 MOHM SMD	874
RLB1112V4-102J J.W. Miller / Bourns	FIXED IND 1MH 510MA 1.4 OHM TH	1033
LBC2518T3R3M TAIYO YUDEN	FIXED IND 3.3UH 560MA 208 MOHM	7480
74456168 Würth Elektronik Midcom	FIXED IND 68UH 1.6A 240 MOHM SMD	627
IMC1210EB1R5J Vishay / Dale	FIXED IND 1.5UH 370MA 850 MOHM	0
LQH55DN680M03L TOKO / Murata	FIXED IND 68UH 640MA 938 MOHM	350
LQP02HQ0N8W02L TOKO / Murata	FIXED IND 0.8NH 900MA 50MOHM SMD	0
MLF1608A2R2M TDK Corporation	FIXED IND 2.2UH 30MA 1 OHM SMD	501
AIAP-03-330K Abracon	FIXED IND 33UH 4.83A 32 MOHM TH	0
SDS680R-152M API Delevan	FIXED IND 1.5UH 2.8A 45 MOHM SMD	4363
B82477P4223M000 TDK EPCOS	FIXED IND 22UH 4.15A 35 MOHM SMD	272
PA4303.822NLT PulseLarsen Antenna	FIXED IND 8.2UH 4A 31 MOHM SMD	0
5022-113F API Delevan	FIXED IND 11UH 565MA 1.05 OHM	0
IHLP2020CZET3R3M01 Vishay / Dale	FIXED IND 3.3UH 5A 54.7MOHM SMD	1941

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