Fixed Inductors

Part Number	Description / PDF	Quantity
RCP1317NP-101M Sumida Corporation	FIXED IND 100UH 2.3A 125 MOHM TH	0
CDEP147NP-0R3NC-73 Sumida Corporation	FIXED IND 300NH 23A 1.18 MOHM	0
CDH53NP-560KC Sumida Corporation	FIXED IND 56UH 500MA 870 MOHM	0
CR75NP-471KC Sumida Corporation	FIXED IND 470UH 340MA 1.96 OHM	0
54060563400 Sumida Corporation	FIXED IND 5.6NH 840MA 40 MOHM	0
CDEP134NP-0R4NC Sumida Corporation	FIXED IND 400NH 18.5A 1.9 MOHM	0
CDRH2D09NP-6R8MC Sumida Corporation	FIXED IND 6.8UH 530MA 340 MOHM	226
0518CDMCCDS-3R3MC Sumida Corporation	FIXED IND 3.3UH 4.2A 58 MOHM	8026
CDRH127/LDNP-680MC Sumida Corporation	FIXED IND 68UH 2.6A 120 MOHM SMD	1450
CDRH74NP-680MC-B Sumida Corporation	FIXED IND 68UH 690MA 380 MOHM	6913
CDRH62BNP-560MC-B Sumida Corporation	FIXED IND 56UH 460MA 780 MOHM	0
CDRR75NP-680MC Sumida Corporation	FIXED IND 68UH 930MA 256 MOHM	0
CDR63BNP-680LC Sumida Corporation	FIXED IND 68UH 420MA 820 MOHM	0
CD73NP-101KC Sumida Corporation	FIXED IND 100UH 510MA 481 MOHM	0
CDRH124NP-3R9MC Sumida Corporation	FIXED IND 3.9UH 6.5A 15 MOHM SMD	225
CEP125NP-03RNC-UD Sumida Corporation	FIXED IND 350NH 18.5A 1.8 MOHM	0
CDR6D23MNNP-0R6NC Sumida Corporation	FIXED IND 600NH 4.6A 20 MOHM SMD	0
CD30D22HF-150MC Sumida Corporation	FIXED IND 15UH 830MA 388 MOHM	0
CDH115NP-120MC Sumida Corporation	FIXED IND 12UH 2.8A 33 MOHM SMD	0
CDRH3D18NP-3R0NC Sumida Corporation	FIXED IND 3UH 1.8A 69 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