Fixed Inductors

Part Number	Description / PDF	Quantity
0819-54K API Delevan	FIXED IND 18UH 112MA 3.8 OHM TH	0
M27/367-01 API Delevan	FIXED IND 220NH 7A 8 MOHM SMD	71
P1330-103J API Delevan	FIXED IND 10UH 946MA 216 MOHM	0
1812R-103K API Delevan	FIXED IND 10UH 354MA 1.6 OHM SMD	0
8532R-45L API Delevan	FIXED IND 4.7MH 190MA 10.1 OHM	0
SP1812R-184K API Delevan	FIXED IND 180UH 172MA 6.7 OHM	604
1812R-392K API Delevan	FIXED IND 3.9UH 472MA 900 MOHM	0
5022-241G API Delevan	FIXED IND 240NH 2.47A 60 MOHM	0
SPD125R-222M API Delevan	FIXED IND 2.2UH 7A 20 MOHM SMD	0
4922-27L API Delevan	FIXED IND 150UH 630MA 998 MOHM	0
4590-336K API Delevan	FIXED IND 33MH 160MA 25.7 OHM TH	0
8532R-48J API Delevan	FIXED IND 8.2MH 130MA 20.8 OHM	0
0819-14H API Delevan	FIXED IND 390NH 420MA 590 MOHM	0
ER1537-08KS API Delevan	FIXED IND 680NH 1.1A 150 MOHM TH	450
4922R-14L API Delevan	FIXED IND 12UH 2.24A 79 MOHM SMD	0
2727-19H API Delevan	FIXED IND 330UH 100MA 19 OHM TH	0
5022-563G API Delevan	FIXED IND 56UH 335MA 3 OHM SMD	0
103-123H API Delevan	FIXED IND 12UH 160MA 3.8 OHM SMD	0
S1210R-683G API Delevan	FIXED IND 68UH 152MA 7 OHM SMD	0
5022-391F API Delevan	FIXED IND 390NH 1.915A 100 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