Fixed Inductors

Part Number	Description / PDF	Quantity
1210R-562F API Delevan	FIXED IND 5.6UH 341MA 1.6 OHM	0
SP1210-273G API Delevan	FIXED IND 27UH 249MA 2.5 OHM SMD	0
SP1812-224G API Delevan	FIXED IND 220UH 164MA 7.5 OHM	0
8532-28L API Delevan	FIXED IND 180UH 990MA 362 MOHM	0
ER1641-105KR API Delevan	FIXED IND 1MH 70MA 17.5 OHM TH	0
SP1812-392J API Delevan	FIXED IND 3.9UH 1A 200 MOHM SMD	0
4590R-106K API Delevan	FIXED IND 10MH 300MA 7.3 OHM TH	480
2474R-19L API Delevan	FIXED IND 33UH 2.17A 75 MOHM TH	4069
1812R-270J API Delevan	FIXED IND 27NH 1A 150 MOHM SMD	0
0819-80J API Delevan	FIXED IND 220UH 42.5MA 26.5 OHM	0
SP1210-124H API Delevan	FIXED IND 120UH 147MA 9.6 OHM	0
S1812-393J API Delevan	FIXED IND 39UH 250MA 3.2 OHM SMD	0
2474-38L API Delevan	FIXED IND 1.2MH 370MA 2.55 OHM	0
SP1210R-154H API Delevan	FIXED IND 150UH 124MA 13.5 OHM	0
P3519R-123J API Delevan	FIXED IND 12UH 1.01A 289 MOHM	0
5022-514J API Delevan	FIXED IND 510UH 139MA 18.8 OHM	0
HRSPD127-223M API Delevan	FIXED IND 22UH 3.2A 53MOHM SMD	250
P1330-334K API Delevan	FIXED IND 330UH 179MA 4.8 OHM	0
5022R-362F API Delevan	FIXED IND 3.6UH 415MA 2.15 OHM	0
8532-42J API Delevan	FIXED IND 2.7MH 250MA 5.8 OHM	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