Fixed Inductors

Part Number	Description / PDF	Quantity
SP1812-822J API Delevan	FIXED IND 8.2UH 842MA 280 MOHM	0
M27/367-11 API Delevan	FIXED IND 1.5UH 4.45A 20 MOHM	1326
S1008R-471G API Delevan	FIXED IND 470NH 815MA 170 MOHM	0
1537-10K API Delevan	FIXED IND 820NH 1.02A 220 MOHM	0
8532-22K API Delevan	FIXED IND 56UH 1.65A 130 MOHM	0
P3519R-185K API Delevan	FIXED IND 1.8MH 90MA 35.9 OHM	0
HF1008-221H API Delevan	FIXED IND 220NH 360MA 1.15 OHM	0
DC780-822L API Delevan	FIXED IND 8.2UH 11.4A 7 MOHM TH	0
5022-511F API Delevan	FIXED IND 510NH 1.68A 130 MOHM	0
S1210R-392K API Delevan	FIXED IND 3.9UH 441MA 830 MOHM	474
103-153F API Delevan	FIXED IND 15UH 135MA 5.6 OHM SMD	0
4922-18L API Delevan	FIXED IND 27UH 1.48A 179 MOHM	0
2474-11L API Delevan	FIXED IND 6.8UH 3.69A 26 MOHM TH	0
1840-06M API Delevan	FIXED IND 470NH 1.86A 80 MOHM TH	0
ER1025-60KR API Delevan	FIXED IND 47UH 110MA 4.5 OHM TH	0
8532R-51L API Delevan	FIXED IND 15MH 100MA 36 OHM SMD	0
P1812-683G API Delevan	FIXED IND 68UH 220MA 3.408 OHM	0
ER1641-105KS API Delevan	FIXED IND 1MH 70MA 17.5 OHM TH	0
SPD127R-564M API Delevan	FIXED IND 560UH 750MA 1.15 OHM	0
5500R-124K API Delevan	FIXED IND 120UH 2.96A 113 MOHM	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