Fixed Inductors

Part Number	Description / PDF	Quantity
CD104NP-151KC Sumida Corporation	FIXED IND 150UH 610MA 544 MOHM	0
CDEP134NP-0R3NC-H Sumida Corporation	FIXED IND 300NH 18.5A 1.9 MOHM	0
54060393400 Sumida Corporation	FIXED IND 3.9NH 900MA 35 MOHM	0
CDRH3D18NP-4R7NC Sumida Corporation	FIXED IND 4.7UH 1.35A 107.5 MOHM	0
CDEP134NP-0R9MC Sumida Corporation	FIXED IND 900NH 17A 2.5 MOHM SMD	0
CDR125NP-100MC Sumida Corporation	FIXED IND 10UH 2.65A 50 MOHM SMD	0
CDRH124NP-4R7MC Sumida Corporation	FIXED IND 4.7UH 5.7A 18 MOHM SMD	0
CDR125NP-470MC Sumida Corporation	FIXED IND 47UH 1.5A 120 MOHM SMD	0
CDH115NP-181KC Sumida Corporation	FIXED IND 180UH 720MA 450 MOHM	0
CR32NP-2R7MC Sumida Corporation	FIXED IND 2.7UH 1.24A 111 MOHM	0
CR32NP-680KC Sumida Corporation	FIXED IND 68UH 275MA 1.45 OHM	0
CDR105NP-221MC Sumida Corporation	FIXED IND 220UH 540MA 690 MOHM	0
CDH115NP-150MC Sumida Corporation	FIXED IND 15UH 2.5A 39 MOHM SMD	0
CDR125NP-181MC Sumida Corporation	FIXED IND 180UH 770MA 480 MOHM	0
CDRH73NP-680MC-B Sumida Corporation	FIXED IND 68UH 610MA 520 MOHM	0
CDR6D23MNNP-1R0NC Sumida Corporation	FIXED IND 1UH 3.9A 25 MOHM SMD	0
RCH895NP-151K Sumida Corporation	FIXED IND 150UH 610MA 270 MOHM	0
CDRH8D58/LDNP-680NC Sumida Corporation	FIXED IND 68UH 1.7A 130 MOHM SMD	13431
CDRH74NP-561MC-B Sumida Corporation	FIXED IND 560UH 230MA 3.62 OHM	0
CDRH74NP-151MC-B Sumida Corporation	FIXED IND 150UH 460MA 880 MOHM	2911

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