Fixed Inductors

Part Number	Description / PDF	Quantity
CDR125NP-271MC Sumida Corporation	FIXED IND 270UH 630MA 700 MOHM	0
CD30D22HF-390MC Sumida Corporation	FIXED IND 39UH 480MA 915 MOHM	0
CDRH70D45BT150NP-151MC Sumida Corporation	FIXED IND 150UH 1.05A 430 MOHM	1990
CDRH5D18NP-120NC Sumida Corporation	FIXED IND 12UH 1.1A 153 MOHM SMD	232
CDR7D43MNNP-390NC Sumida Corporation	FIXED IND 39UH 1.1A 175 MOHM SMD	0
252010CDMCDDS-R68MC Sumida Corporation	FIXED IND 680NH 4.2A 37 MOHM SMD	5999
CDRH105RNP-330NC Sumida Corporation	FIXED IND 33UH 2.5A 84 MOHM SMD	184
CDRH127NP-221MC Sumida Corporation	FIXED IND 220UH 1.16A 390 MOHM	0
CDRH127/LDNP-102MC Sumida Corporation	FIXED IND 1MH 700MA 1.5 OHM SMD	1433
CDRH4D28CNP-680PC Sumida Corporation	FIXED IND 68UH 490MA 625 MOHM	0
0830CDMCCDS-100MC Sumida Corporation	FIXED IND 10UH 4.5A 72 MOHM SMD	1431
CD75NP-220KC Sumida Corporation	FIXED IND 22UH 1.5A 110 MOHM SMD	0
CDRH4D22NP-180NC Sumida Corporation	FIXED IND 18UH 1.41A 168.7 MOHM	0
CDRH2D11/HPNP-4R7NC Sumida Corporation	FIXED IND 4.7UH 850MA 238 MOHM	401
CDRH2D18/HPNP-4R7NC Sumida Corporation	FIXED IND 4.7UH 1.2A 140 MOHM	0
CDRH8D38NP-150NC Sumida Corporation	FIXED IND 15UH 2.5A 67 MOHM SMD	1956
54068203400 Sumida Corporation	FIXED IND 82NH 220MA 590 MOHM	0
CDRH2D18/LDNP-330NC Sumida Corporation	FIXED IND 33UH 560MA 460 MOHM	0
CD43NP-3R3MC Sumida Corporation	FIXED IND 3.3UH 2A 86.2 MOHM SMD	0
CDH53NP-221JC Sumida Corporation	FIXED IND 220UH 260MA 3.73 OHM	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