Fixed Inductors

Part Number	Description / PDF	Quantity
1812R-820K API Delevan	FIXED IND 82NH 700MA 250 MOHM	0
1812-122G API Delevan	FIXED IND 1.2UH 604MA 550 MOHM	0
1537-80J API Delevan	FIXED IND 120UH 140MA 5.2 OHM TH	0
1025R-68K API Delevan	FIXED IND 100UH 84MA 8 OHM TH	2249
2727-17H API Delevan	FIXED IND 220UH 96MA 20 OHM TH	0
S1812R-682K API Delevan	FIXED IND 6.8UH 408MA 1.2 OHM	3240
P1330R-562K API Delevan	FIXED IND 5.6UH 1.11A 145 MOHM	0
HTPT66R-104K API Delevan	FIXED IND 100UH 1.9A 145 MOHM TH	245
1812-121G API Delevan	FIXED IND 120NH 818MA 300 MOHM	0
5022-822G API Delevan	FIXED IND 8.2UH 748MA 600 MOHM	0
5022-681J API Delevan	FIXED IND 680NH 1.555A 150 MOHM	0
4590R-275K API Delevan	FIXED IND 2.7MH 560MA 2.13 OHM	0
5500R-336K API Delevan	FIXED IND 33MH 200MA 25.7 OHM	0
4426R-8 API Delevan	FIXED IND 28NH 3A SMD	4537
5500R-105K API Delevan	FIXED IND 1MH 1.08A 844 MOHM SMD	0
1008R-393J API Delevan	FIXED IND 39UH 125MA 9 OHM SMD	0
S1210R-103K API Delevan	FIXED IND 10UH 291MA 1.9 OHM SMD	13687
S1008R-621F API Delevan	FIXED IND 620NH 770MA 190 MOHM	0
HF1008R-122F API Delevan	FIXED IND 1.2UH 320MA 1.45 OHM	0
S1008R-682G API Delevan	FIXED IND 6.8UH 250MA 1.8 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