Fixed Inductors

Part Number	Description / PDF	Quantity
LPWI201210SR47T Wickmann / Littelfuse	FIXED IND 470NH 4A 33MOHM SMD	0
LPWI201208SR68T Wickmann / Littelfuse	FIXED IND 680NH 2.5A 65MOHM SMD	0
LPWI252010S1R0T Wickmann / Littelfuse	FIXED IND 1UH 3.5A 50 MOHM SMD	1770
LPWI201610TAR47T Wickmann / Littelfuse	FIXED IND 470NH 3.2A 40MOHM SMD	0
LPWI160808H1R0T Wickmann / Littelfuse	FIXED IND 1UH 1.7A 135MOHM SMD	2000
LPWI252010S2R2T Wickmann / Littelfuse	FIXED IND 2.2UH 2.5A 110 MOHM	875
LPWI252010HR47T Wickmann / Littelfuse	FIXED IND 470NH 5.2A 27 MOHM SMD	0
LPWI201610BR47T Wickmann / Littelfuse	FIXED IND 470NH 4.8A 27MOHM SMD	0
LPWI252010SR33T Wickmann / Littelfuse	FIXED IND 330NH 5.8A 25 MOHM SMD	0
LPWI201608N1R5T Wickmann / Littelfuse	FIXED IND 1.5UH 1.9A 120MOHM SMD	0
LPWI252010S1R5T Wickmann / Littelfuse	FIXED IND 1.5UH 2.8A 80 MOHM SMD	0
LPWI201208SR24T Wickmann / Littelfuse	FIXED IND 240NH 3.9A 22MOHM SMD	2830
LPWI252010NR68T Wickmann / Littelfuse	FIXED IND 680NH 3.5A 37MOHM SMD	0
LPWI252010S4R7T Wickmann / Littelfuse	FIXED IND 4.7UH 1.5A 245MOHM SMD	4
LPWI160808HR47T Wickmann / Littelfuse	FIXED IND 470NH 2.9A 45MOHM SMD	0
LPWI201610TR47T Wickmann / Littelfuse	FIXED IND 470NH 3.6A 25MOHM SMD	0
LPWI201608S1R0T Wickmann / Littelfuse	FIXED IND 1UH 3A 65 MOHM SMD	0
LPWI201610B1R0T Wickmann / Littelfuse	FIXED IND 1UH 3.2A 46MOHM SMD	0
LPWI201608H1R0T Wickmann / Littelfuse	FIXED IND 1UH 3.2A 50MOHM SMD	9486
LPWI252010B2R2T Wickmann / Littelfuse	FIXED IND 2.2UH 2.3A 95MOHM SMD	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