Fixed Inductors

Part Number	Description / PDF	Quantity
DC630R-472M API Delevan	FIXED IND 4.7UH 11.7A 7 MOHM TH	0
2727-20F API Delevan	FIXED IND 390UH 93MA 22 OHM TH	0
1812-683G API Delevan	FIXED IND 68UH 183MA 6 OHM SMD	0
S1210R-391K API Delevan	FIXED IND 390NH 692MA 400 MOHM	13661
1840-09K API Delevan	FIXED IND 820NH 1.24A 180 MOHM	0
1812-223G API Delevan	FIXED IND 22UH 250MA 3.2 OHM SMD	0
5500R-334K API Delevan	FIXED IND 330UH 1.97A 257 MOHM	0
HTPT66-122K API Delevan	FIXED IND 1.2UH 15.3A 2.9 MOHM	0
8532R-29K API Delevan	FIXED IND 220UH 840MA 505 MOHM	0
5022R-821H API Delevan	FIXED IND 820NH 1.3A 220 MOHM	0
S1210R-681G API Delevan	FIXED IND 680NH 590MA 550 MOHM	0
HF1008-911G API Delevan	FIXED IND 910NH 270MA 2.05 OHM	0
SP1008R-823K API Delevan	FIXED IND 82UH 107MA 9.9 OHM SMD	0
1210-033K API Delevan	FIXED IND 3.3NH 1.562A 50 MOHM	0
S1812R-684K API Delevan	FIXED IND 680UH 79MA 32 OHM SMD	426
4922R-33L API Delevan	FIXED IND 470UH 350MA 3.25 OHM	1334
S1812R-682H API Delevan	FIXED IND 6.8UH 408MA 1.2 OHM	0
5022R-562H API Delevan	FIXED IND 5.6UH 1.03A 320 MOHM	0
8532-35L API Delevan	FIXED IND 680UH 490MA 1.5 OHM	0
103-822G API Delevan	FIXED IND 8.2UH 195MA 2.5 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