Fixed Inductors

Part Number	Description / PDF	Quantity
SPD125-824M API Delevan	FIXED IND 820UH 450MA 1.65 OHM	449
0819-40F API Delevan	FIXED IND 4.7UH 150MA 2.1 OHM TH	0
S1210-331F API Delevan	FIXED IND 330NH 740MA 350 MOHM	0
SP1812R-104G API Delevan	FIXED IND 100UH 250MA 3.2 OHM	0
S1210-152J API Delevan	FIXED IND 1.5UH 532MA 570 MOHM	0
S1008R-101J API Delevan	FIXED IND 100NH 1.12A 90 MOHM	0
8532R-51K API Delevan	FIXED IND 15MH 100MA 36 OHM SMD	0
5022R-331J API Delevan	FIXED IND 330NH 2.015A 90 MOHM	0
4922-471L API Delevan	FIXED IND 470NH 6A 10 MOHM SMD	0
8532R-36J API Delevan	FIXED IND 820UH 420MA 1.98 OHM	0
0819-34H API Delevan	FIXED IND 2.7UH 236MA 850 MOHM	0
103-152KS API Delevan	FIXED IND 1.5UH 340MA 840 MOHM	0
1210R-473F API Delevan	FIXED IND 47UH 163MA 7 OHM SMD	0
HF1008R-182G API Delevan	FIXED IND 1.8UH 305MA 1.6 OHM	0
S1812R-154H API Delevan	FIXED IND 150UH 158MA 8 OHM SMD	0
P1330-222K API Delevan	FIXED IND 2.2UH 1.69A 75 MOHM	0
1840-28K API Delevan	FIXED IND 8.2UH 560MA 400 MOHM	0
5022R-511F API Delevan	FIXED IND 510NH 1.68A 130 MOHM	0
SP1210R-682H API Delevan	FIXED IND 6.8UH 576MA 630 MOHM	0
1812-472J API Delevan	FIXED IND 4.7UH 448MA 1 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