Fixed Inductors

Part Number	Description / PDF	Quantity
4590-275K API Delevan	FIXED IND 2.7MH 560MA 2.13 OHM	0
SP1812R-272H API Delevan	FIXED IND 2.7UH 1.11A 160 MOHM	0
103-182J API Delevan	FIXED IND 1.8UH 325MA 920 MOHM	0
ER1641-204JS API Delevan	FIXED IND 200UH 125MA 5 OHM TH	0
8532-24J API Delevan	FIXED IND 82UH 1.53A 152 MOHM	0
5022-104H API Delevan	FIXED IND 100UH 275MA 4.5 OHM	0
4590R-105K API Delevan	FIXED IND 1MH 890MA 844 MOHM TH	1719
SP1210-681G API Delevan	FIXED IND 680NH 1.32A 119 MOHM	0
5022-394G API Delevan	FIXED IND 390UH 149MA 16.3 OHM	0
5022R-623J API Delevan	FIXED IND 62UH 328MA 3.15 OHM	0
S1812R-334F API Delevan	FIXED IND 330UH 129MA 12 OHM SMD	0
1210R-471J API Delevan	FIXED IND 470NH 644MA 500 MOHM	0
103-271HS API Delevan	FIXED IND 270NH 650MA 230 MOHM	0
SP1210R-392J API Delevan	FIXED IND 3.9UH 665MA 470 MOHM	0
1812-394H API Delevan	FIXED IND 390UH 100MA 20 OHM SMD	0
P1330R-104K API Delevan	FIXED IND 100UH 347MA 1.68 OHM	233
1210-123K API Delevan	FIXED IND 12UH 272MA 2.5 OHM SMD	0
1008R-471K API Delevan	FIXED IND 470NH 846MA 210 MOHM	1360
1330-72K API Delevan	FIXED IND 150UH 61MA 15 OHM SMD	0
P3519R-102J API Delevan	FIXED IND 1UH 3A 33 MOHM SMD	124

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