Fixed Inductors

Part Number	Description / PDF	Quantity
SDEM25201B-1R0MS Delta Electronics	FIXED IND 1UH 3.7A 52.5MOHM SMD	3884
HMLQ20161T-R47MDR Delta Electronics	FIXED IND 470NH 4.4A 32MOHM SMD	4658
0402HS-121EGTS Delta Electronics	FIXED IND 120NH 50MA 2.66 OHM	7690
0805CS-111EJTS Delta Electronics	FIXED IND 110NH 400MA 480 MOHM	3948
0805CS-220EKTS Delta Electronics	FIXED IND 22NH 500MA 220 MOHM	3930
0402HM-2N9ECTS Delta Electronics	FIXED IND 2.9NH 750MA 70MOHM SMD	7900
0402HP-150EKTS Delta Electronics	FIXED IND 15NH 1.1A 110 MOHM SMD	7864
0805CS-272EKTS Delta Electronics	FIXED IND 2.7UH 150MA 3.1 OHM	3982
0402HM-910EGTS Delta Electronics	FIXED IND 91NH 125MA 2.38 OHM	7980
SDED20161T-3R3MS Delta Electronics	FIXED IND 3.3UH 1.05A 292MOHM SM	5950
0402HP-3N9EHTS Delta Electronics	FIXED IND 3.9NH 1.7A 45 MOHM SMD	7870
0402HM-400EJTS Delta Electronics	FIXED IND 40NH 250MA 700 MOHM	7990
0402HS-3N9EGTS Delta Electronics	FIXED IND 3.9NH 840MA 66 MOHM	5196
0805CT-151EJTS Delta Electronics	FIXED IND 150NH 300MA 800 MOHM	3860
0402HS-360EGTS Delta Electronics	FIXED IND 36NH 320MA 440MOHM SMD	8000
VCMT063T-100MN5T Delta Electronics	FIXED IND 10UH 4A 70.5MOHM SMD	20000
SDET25201T-4R7MS Delta Electronics	FIXED IND 4.7UH 1.08A 323MOHM SM	5903
0805CS-561EGTS Delta Electronics	FIXED IND 560NH 230MA 1.9 OHM	1965
0402HP-330EGTS Delta Electronics	FIXED IND 33NH 490MA 330 MOHM	7850
0402HM-720EJTS Delta Electronics	FIXED IND 72NH 135MA 2.1 OHM SMD	8000

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