Fixed Inductors

Part Number	Description / PDF	Quantity
CDMT40D20HF-R63NC Sumida Corporation	FIXED IND 630NH 6.1A 10.3 MOHM	974
CD43NP-330KC Sumida Corporation	FIXED IND 33UH 560MA 540 MOHM	0
CEP125NP-3R2MC-U Sumida Corporation	FIXED IND 3.2UH 9.9A 8 MOHM SMD	0
CDRH6D38NP-8R7NC Sumida Corporation	FIXED IND 8.7UH 2.2A 34 MOHM SMD	0
CDRH70D45BT150NP-2R2NC Sumida Corporation	FIXED IND 2.2UH 7.6A 10MOHM SMD	1830
CR54NP-470LC Sumida Corporation	FIXED IND 47UH 720MA 370 MOHM	459
RCH895NP-330K Sumida Corporation	FIXED IND 33UH 1.1A 70 MOHM TH	448
0420CDMCCDS-R10MC Sumida Corporation	FIXED IND 100NH 17A 4 MOHM SMD	2160
54060333400 Sumida Corporation	FIXED IND 3.3NH 800MA 40 MOHM	0
CDRH60D45BT150NP-1R5NC Sumida Corporation	FIXED IND 1.5UH 4.5A 16.9 MOHM	2000
CR54NP-181KC Sumida Corporation	FIXED IND 180UH 380MA 1.38 OHM	0
CDR6D23MNNP-150NC Sumida Corporation	FIXED IND 15UH 1.1A 133.8 MOHM	0
0830CDMCCDS-R33MC Sumida Corporation	FIXED IND 330NH 25A 2.6 MOHM SMD	1960
CR43NP-390KC Sumida Corporation	FIXED IND 39UH 520MA 587 MOHM	0
CDR7D43MNNP-270NC Sumida Corporation	FIXED IND 27UH 1.25A 143.6 MOHM	0
CDRH5D16NP-820MC Sumida Corporation	FIXED IND 82UH 420MA 1.06 OHM	0
CR75NP-470KC Sumida Corporation	FIXED IND 47UH 1.1A 180 MOHM SMD	5389
CDH115NP-820KC Sumida Corporation	FIXED IND 82UH 1.04A 210 MOHM	0
CDR6D23MNNP-5R1NC Sumida Corporation	FIXED IND 5.1UH 1.9A 60 MOHM SMD	0
CDRH127/LDNP-7R4NC Sumida Corporation	FIXED IND 7.4UH 7.4A 17.7 MOHM	6

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