Fixed Inductors

Part Number	Description / PDF	Quantity
77F5R6K-TR-RC J.W. Miller / Bourns	FIXED IND 5.6UH 590MA 450MOHM TH	0
2221-V-RC J.W. Miller / Bourns	FIXED IND 560UH 2.2A 210 MOHM TH	0
2200LL-8R2-H-RC J.W. Miller / Bourns	FIXED IND 8.2UH 15.1A 5 MOHM TH	0
SRR1210-2R2Y J.W. Miller / Bourns	FIXED IND 2.2UH 9.5A 9 MOHM SMD	0
SDR0805-472KL J.W. Miller / Bourns	FIXED IND 4.7MH 80MA 21 OHM SMD	3438
RL875-561K-RC J.W. Miller / Bourns	FIXED IND 560UH 360MA 1.72OHM TH	0
SRP4018FA-R60M J.W. Miller / Bourns	FIXED INDUCTOR SMD	297
2100LL-1R0-V-RC J.W. Miller / Bourns	FIXED IND 1UH 21.4A 2 MOHM TH	0
CC453232-2R7KL J.W. Miller / Bourns	FIXED IND 2.7UH 800MA 200MOHM SM	0
SRP0410-R47K J.W. Miller / Bourns	FIXED IND 470NH 5.2A 35.3 MOHM	300
SRP1265A-2R2M J.W. Miller / Bourns	FIXED IND 2.2UH 22A 4.2 MOHM SMD	0
SRP0420-3R3K J.W. Miller / Bourns	FIXED IND 3.3UH 3.9A 52 MOHM SMD	353
CS160808-1R5K J.W. Miller / Bourns	FIXED IND 1.5UH 50MA 650MOHM SMD	0
SRR1208-822KL J.W. Miller / Bourns	FIXED IND 8.2MH 200MA 17 OHM SMD	677
SRR1260-2R4Y J.W. Miller / Bourns	FIXED IND 2.4UH 7.8A 11.5MOHM SM	0
SRR1260A-180M J.W. Miller / Bourns	FIXED IND 18UH 4.2A 36 MOHM SMD	76
SRP1270-3R3M J.W. Miller / Bourns	FIXED IND 3.3UH 18A 6.6 MOHM SMD	9
SRR1280-331K J.W. Miller / Bourns	FIXED IND 330UH 1.1A 600MOHM SMD	4063
SRP7028A-1R0M J.W. Miller / Bourns	FIXED IND 1UH 11A 10 MOHM SMD	21535
CW105550A-3N3J J.W. Miller / Bourns	FIXED IND 3.3NH 840MA 66MOHM SMD	910

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