Fixed Inductors

Part Number	Description / PDF	Quantity
2474R-05L API Delevan	FIXED IND 2.2UH 5.22A 13 MOHM TH	272
1812R-331K API Delevan	FIXED IND 330NH 604MA 550 MOHM	0
S1008R-271H API Delevan	FIXED IND 270NH 900MA 140 MOHM	0
S1008R-751J API Delevan	FIXED IND 750NH 735MA 210 MOHM	0
0819-32K API Delevan	FIXED IND 2.2UH 257MA 720 MOHM	0
5022-124G API Delevan	FIXED IND 120UH 255MA 5.2 OHM	0
5022R-394G API Delevan	FIXED IND 390UH 149MA 16.3 OHM	0
5022-564H API Delevan	FIXED IND 560UH 136MA 19.5 OHM	0
1025-00K API Delevan	FIXED IND 150NH 1.23A 100 MOHM	764
1812R-224F API Delevan	FIXED IND 220UH 142MA 10 OHM SMD	0
HF1008R-821J API Delevan	FIXED IND 820NH 273MA 2 OHM SMD	0
103-182FS API Delevan	FIXED IND 1.8UH 325MA 920 MOHM	0
S1008-222K API Delevan	FIXED IND 2.2UH 375MA 800 MOHM	0
1210-047M API Delevan	FIXED IND 4.7NH 1.562A 50 MOHM	0
HF1008R-561F API Delevan	FIXED IND 560NH 300MA 1.65 OHM	0
ER1641-512JS API Delevan	FIXED IND 5.1UH 335MA 720 MOHM	453
HF1008-390M API Delevan	FIXED IND 39NH 870MA 160 MOHM	0
SP1812-124J API Delevan	FIXED IND 120UH 210MA 4.6 OHM	0
2474-36L API Delevan	FIXED IND 820UH 420MA 1.98 OHM	261
8532R-37L API Delevan	FIXED IND 1MH 390MA 2.3 OHM SMD	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