Fixed Inductors

Part Number	Description / PDF	Quantity
1210R-221F API Delevan	FIXED IND 220NH 805MA 320 MOHM	0
103-682J API Delevan	FIXED IND 6.8UH 210MA 2.2 OHM	0
P1330-563J API Delevan	FIXED IND 56UH 442MA 900 MOHM	0
103-121JS API Delevan	FIXED IND 120NH 880MA 125 MOHM	0
0819-78F API Delevan	FIXED IND 180UH 49MA 20 OHM TH	0
SP1210R-102H API Delevan	FIXED IND 1UH 1.19A 147 MOHM SMD	0
4590R-564K API Delevan	FIXED IND 560UH 1.15A 504 MOHM	2525
P1812R-183G API Delevan	FIXED IND 18UH 400MA 875 MOHM	0
S1812R-224K API Delevan	FIXED IND 220UH 149MA 9 OHM SMD	0
8532-51H API Delevan	FIXED IND 15MH 100MA 36 OHM SMD	0
S1210-562H API Delevan	FIXED IND 5.6UH 352MA 1.3 OHM	0
SP1812-123K API Delevan	FIXED IND 12UH 767MA 340 MOHM	0
1210-683K API Delevan	FIXED IND 68UH 144MA 9 OHM SMD	0
DC780R-154K API Delevan	FIXED IND 150UH 4A 98 MOHM TH	1362
8532-18K API Delevan	FIXED IND 27UH 2.25A 70 MOHM SMD	0
P3519-474J API Delevan	FIXED IND 470UH 160MA 11.3 OHM	0
1812R-823K API Delevan	FIXED IND 82UH 169MA 7 OHM SMD	0
SP1812-182K API Delevan	FIXED IND 1.8UH 1.36A 110 MOHM	0
1812-823J API Delevan	FIXED IND 82UH 169MA 7 OHM SMD	0
S1812R-331G API Delevan	FIXED IND 330NH 952MA 220 MOHM	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