Fixed Inductors

Part Number	Description / PDF	Quantity
CDRH125NP-821MC Sumida Corporation	FIXED IND 820UH 430MA 1.34 OHM	0
CEP125NP-100MC Sumida Corporation	FIXED IND 10UH 7.6A 13.5 MOHM	154
CDRH2D14NP-R21NC Sumida Corporation	FIXED IND 210NH 4.74A 21 MOHM	0
CDMT40D20HF-R47NC Sumida Corporation	FIXED IND 470NH 6.8A 8.3 MOHM	1564
CDRH5D28RNP-8R0NC Sumida Corporation	FIXED IND 8UH 1.5A 49.9 MOHM SMD	0
CDMC6D28NP-2R2MC Sumida Corporation	FIXED IND 2.2UH 6A 19.3 MOHM SMD	1509
CDEP147NP-0R7MC-73 Sumida Corporation	FIXED IND 700NH 21.5A 1.46 MOHM	0
CDRH3D18NP-6R8NC Sumida Corporation	FIXED IND 6.8UH 1.1A 150 MOHM	0
CD30D22HF-1R0MC Sumida Corporation	FIXED IND 1UH 3.46A 35.9 MOHM	0
CDRH4D28CNP-220PC Sumida Corporation	FIXED IND 22UH 850MA 207 MOHM	0
CR54NP-8R5MC Sumida Corporation	FIXED IND 8.5UH 1.84A 67.6 MOHM	0
CD30D22HF-1R5MC Sumida Corporation	FIXED IND 1.5UH 3A 48.7 MOHM	0
CDRR75NP-151MC Sumida Corporation	FIXED IND 150UH 660MA 485 MOHM	0
CDRH74NP-390MC-B Sumida Corporation	FIXED IND 39UH 910MA 230 MOHM	0
CDRH125NP-331MC Sumida Corporation	FIXED IND 330UH 680MA 510 MOHM	3034
CDRH8D58/LDNP-3R9NC Sumida Corporation	FIXED IND 3.9UH 6.3A 16.3 MOHM	0
55081003400 Sumida Corporation	FIXED IND 10NH 700MA 60 MOHM SMD	0
CD43NP-120MC Sumida Corporation	FIXED IND 12UH 970MA 210 MOHM	0
CDRH4D22NP-4R7NC Sumida Corporation	FIXED IND 4.7UH 2.08A 55.9 MOHM	0
CR75NP-121KC Sumida Corporation	FIXED IND 120UH 660MA 470 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