Fixed Inductors

Part Number	Description / PDF	Quantity
RCH664NP-470K Sumida Corporation	FIXED IND 47UH 870MA 230 MOHM TH	0
CDH74NP-271JC Sumida Corporation	FIXED IND 270UH 480MA 1.38 OHM	0
0410CDMCCDS-R68MC Sumida Corporation	FIXED IND 680NH 4A 38.9MOHM SMD	6000
CDR6D23MNNP-8R3NC Sumida Corporation	FIXED IND 8.3UH 1.5A 80 MOHM SMD	0
CDRH62BNP-151MC-B Sumida Corporation	FIXED IND 150UH 280MA 2.18 OHM	0
CDRH73NP-820MC-B Sumida Corporation	FIXED IND 82UH 570MA 690 MOHM	0
CDR7D43MNNP-100NC Sumida Corporation	FIXED IND 10UH 2.5A 48.4 MOHM	46630
CDH115NP-221KC Sumida Corporation	FIXED IND 220UH 660MA 530 MOHM	0
CD75NP-331KC Sumida Corporation	FIXED IND 330UH 400MA 1.26 OHM	0
RCR875DNP-332K Sumida Corporation	FIXED IND 3.3MH 130MA 9.74 OHM	657
CEP125NP-0R3NC-UD Sumida Corporation	FIXED IND 350NH 18.5A 1.8 MOHM	0
CD75NP-270KC Sumida Corporation	FIXED IND 27UH 1.3A 120 MOHM SMD	0
CDMT40D30HF-4R7NC Sumida Corporation	FIXED IND 4.7UH 3.6A 37 MOHM SMD	3850
CR75NP-4R7MC Sumida Corporation	FIXED IND 4.7UH 3.1A 30 MOHM SMD	0
CDRH8D48/ANP-220MC Sumida Corporation	FIXED IND 22UH 1.45A 88 MOHM SMD	0
CDH115NP-470KC Sumida Corporation	FIXED IND 47UH 1.36A 130 MOHM	0
CDR6D23MNNP-470NC Sumida Corporation	FIXED IND 47UH 540MA 456.3 MOHM	0
CDRH73NP-101MC-B Sumida Corporation	FIXED IND 100UH 500MA 790 MOHM	0
CDRH4D28CLDNP-470PC Sumida Corporation	FIXED IND 47UH 860MA 272 MOHM	0
CDRH4D14LDNP-4R7NC Sumida Corporation	FIXED IND 4.7UH 1.9A 66 MOHM SMD	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