Fixed Inductors

Part Number	Description / PDF	Quantity
P1330-472J API Delevan	FIXED IND 4.7UH 1.33A 125 MOHM	0
S1008-152K API Delevan	FIXED IND 1.5UH 545MA 420 MOHM	0
HCTR-684 API Delevan	FIXED IND 29UH 6.57A 25 MOHM SMD	898
SPD127R-393M API Delevan	FIXED IND 39UH 2.8A 80 MOHM SMD	0
S1008R-391G API Delevan	FIXED IND 390NH 840MA 160 MOHM	0
5022-431J API Delevan	FIXED IND 430NH 1.825A 110 MOHM	0
5022R-562G API Delevan	FIXED IND 5.6UH 1.03A 320 MOHM	0
SPD74R-105M API Delevan	FIXED IND 1MH 280MA 6 OHM SMD	548
1210R-102F API Delevan	FIXED IND 1UH 515MA 700 MOHM SMD	0
8532R-18H API Delevan	FIXED IND 27UH 2.25A 70 MOHM SMD	0
S1210R-472F API Delevan	FIXED IND 4.7UH 402MA 1 OHM SMD	0
4590-825K API Delevan	FIXED IND 8.2MH 320MA 6.44 OHM	0
8532R-45H API Delevan	FIXED IND 4.7MH 190MA 10.1 OHM	0
SPD42R-472M API Delevan	FIXED IND 4.7UH 900MA 45 MOHM	500
0819-70G API Delevan	FIXED IND 82UH 54.5MA 16 OHM TH	0
SP1210R-683K API Delevan	FIXED IND 68UH 185MA 6.1 OHM SMD	0
8532R-43H API Delevan	FIXED IND 3.3MH 230MA 6.56 OHM	0
8532-35K API Delevan	FIXED IND 680UH 490MA 1.5 OHM	0
P3519-122K API Delevan	FIXED IND 1.2UH 2.88A 40 MOHM	0
5022R-154H API Delevan	FIXED IND 150UH 237MA 6.05 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