Fixed Inductors

Image	Part Number	Description / PDF	Quantity	Rfq
	P1330-684J API Delevan	FIXED IND 680UH 130MA 8.76 OHM	0
	1812-123G API Delevan	FIXED IND 12UH 317MA 2 OHM SMD	0
	1812-221K API Delevan	FIXED IND 220NH 708MA 400 MOHM	0
	1008R-333J API Delevan	FIXED IND 33UH 135MA 8 OHM SMD	0
	S1210-331K API Delevan	FIXED IND 330NH 740MA 350 MOHM	0
	1210R-563F API Delevan	FIXED IND 56UH 152MA 8 OHM SMD	0
	5022R-153G API Delevan	FIXED IND 15UH 495MA 1.4 OHM SMD	0
	P1812-222K API Delevan	FIXED IND 2.2UH 850MA 268 MOHM	0
	1210-181G API Delevan	FIXED IND 180NH 860MA 280 MOHM	0
	8532-27K API Delevan	FIXED IND 150UH 1.04A 330 MOHM	0
	S1812R-153F API Delevan	FIXED IND 15UH 301MA 2.2 OHM SMD	0
	5022R-182J API Delevan	FIXED IND 1.8UH 755MA 650 MOHM	0
	103-561G API Delevan	FIXED IND 560NH 590MA 278 MOHM	0
	1812R-392F API Delevan	FIXED IND 3.9UH 472MA 900 MOHM	0
	2474R-49L API Delevan	FIXED IND 10MH 120MA 23.4 OHM TH	0
	103-271GS API Delevan	FIXED IND 270NH 650MA 230 MOHM	0
	S1210-822F API Delevan	FIXED IND 8.2UH 308MA 1.7 OHM	0
	P3519-181J API Delevan	FIXED IND 180NH 4.62A 10 MOHM	0
	S1210R-821G API Delevan	FIXED IND 820NH 565MA 600 MOHM	0
	1210-223F API Delevan	FIXED IND 22UH 224MA 3.7 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