Fixed Inductors

Part Number	Description / PDF	Quantity
194A Hammond Manufacturing	FIXED IND 4H 50MA 167 OHM CHASS	1717
1537M Hammond Manufacturing	FIXED IND 250UH 5A 114 MOHM TH	95
1540M15 Hammond Manufacturing	FIXED IND 1.6MH 1.5A 1.27 OHM TH	0
1539M16 Hammond Manufacturing	FIXED IND 500UH 3.7A 129 MOHM TH	0
195B150 Hammond Manufacturing	FIXED IND 500UH 150A 1.8 MOHM	2
1537F Hammond Manufacturing	FIXED IND 20UH 12.5A 13 MOHM TH	23
1537N Hammond Manufacturing	FIXED IND 500UH 3.2A 260 MOHM TH	146
195G50 Hammond Manufacturing	FIXED IND 5MH 50A 21 MOHM CHASS	5
193T Hammond Manufacturing	FIXED IND 50MH 2A 700 MOHM CHASS	6
155C Hammond Manufacturing	FIXED IND 60H 8MA 2.75 KOHM CHAS	5
158M Hammond Manufacturing	FIXED IND 10H 100MA 262 OHM CHAS	10
1540M19 Hammond Manufacturing	FIXED IND 2.25MH 1.75A 920 MOHM	0
1539M23 Hammond Manufacturing	FIXED IND 1MH 3.5A 195 MOHM TH	5
1539M30 Hammond Manufacturing	FIXED IND 2.5MH 2.8A 464 MOHM TH	24
194E Hammond Manufacturing	FIXED IND 30H 100MA 517.2 OHM	9
1538M11 Hammond Manufacturing	FIXED IND 50UH 8A 28 MOHM TH	585
1539M03 Hammond Manufacturing	FIXED IND 25UH 8A 23 MOHM TH	329
1536L Hammond Manufacturing	FIXED IND 4UH 8A 12 MOHM TH	81
195P10 Hammond Manufacturing	FIXED IND 30MH 10A 170 MOHM CHAS	32
195D50 Hammond Manufacturing	FIXED IND 1.4MH 50A 5 MOHM CHASS	3

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