Fixed Inductors

Part Number	Description / PDF	Quantity
S1812-332K API Delevan	FIXED IND 3.3UH 534MA 700 MOHM	0
P1330-103H API Delevan	FIXED IND 10UH 946MA 216 MOHM	0
1812R-821J API Delevan	FIXED IND 820NH 354MA 1.6 OHM	0
1812-101G API Delevan	FIXED IND 100NH 818MA 300 MOHM	0
103-821JS API Delevan	FIXED IND 820NH 430MA 530 MOHM	0
8532-45K API Delevan	FIXED IND 4.7MH 190MA 10.1 OHM	0
1025-58K API Delevan	FIXED IND 39UH 125MA 3.6 OHM TH	0
HTPT66R-122K API Delevan	FIXED IND 1.2UH 15.3A 2.9 MOHM	0
S1008R-223F API Delevan	FIXED IND 22UH 170MA 6 OHM SMD	0
S1812R-123K API Delevan	FIXED IND 12UH 315MA 2 OHM SMD	0
4426-2NC API Delevan	FIXED IND 5NH 3A SMD	0
HF1008-331G API Delevan	FIXED IND 330NH 330MA 1.35 OHM	0
1008-152K API Delevan	FIXED IND 1.5UH 548MA 500 MOHM	0
1812R-682G API Delevan	FIXED IND 6.8UH 409MA 1.2 OHM	0
5500R-273K API Delevan	FIXED IND 27UH 6.3A 25 MOHM SMD	0
S1008R-562J API Delevan	FIXED IND 5.6UH 295MA 1.3 OHM	0
1840-30K API Delevan	FIXED IND 10UH 455MA 600 MOHM TH	1719
ER1025-42KR API Delevan	FIXED IND 8.2UH 155MA 2.7 OHM TH	0
SP1210R-472G API Delevan	FIXED IND 4.7UH 633MA 520 MOHM	0
5022-471F API Delevan	FIXED IND 470NH 1.75A 120 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