Fixed Inductors

Part Number	Description / PDF	Quantity
S1812R-683H API Delevan	FIXED IND 68UH 215MA 4.3 OHM SMD	0
103-331J API Delevan	FIXED IND 330NH 645MA 235 MOHM	0
8532-34H API Delevan	FIXED IND 560UH 560MA 1.14 OHM	0
103-272KS API Delevan	FIXED IND 2.7UH 290MA 1.15 OHM	0
SDS680R-105M API Delevan	FIXED IND 1MH 150MA 3.4 OHM SMD	5008
1812-332H API Delevan	FIXED IND 3.3UH 501MA 800 MOHM	0
S1812R-474H API Delevan	FIXED IND 470UH 91MA 24 OHM SMD	0
103-271K API Delevan	FIXED IND 270NH 650MA 230 MOHM	0
103-120K API Delevan	FIXED IND 12NH 1.19A 69 MOHM SMD	0
S1210-152G API Delevan	FIXED IND 1.5UH 532MA 570 MOHM	0
1210-271H API Delevan	FIXED IND 270NH 759MA 360 MOHM	0
2474R-47L API Delevan	FIXED IND 6.8MH 150MA 15 OHM TH	0
P3519R-221K API Delevan	FIXED IND 220NH 4.39A 15 MOHM	126
1025-70K API Delevan	FIXED IND 120UH 66MA 13 OHM TH	0
SP1812-223H API Delevan	FIXED IND 22UH 509MA 750 MOHM	0
1812-821K API Delevan	FIXED IND 820NH 354MA 1.6 OHM	0
S1210-681H API Delevan	FIXED IND 680NH 590MA 550 MOHM	0
5022-105H API Delevan	FIXED IND 1MH 105MA 33 OHM SMD	0
HF1008-121H API Delevan	FIXED IND 120NH 405MA 910 MOHM	0
0819-00H API Delevan	FIXED IND 100NH 895MA 130 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