Fixed Inductors

Part Number	Description / PDF	Quantity
SDR6603-3R3M J.W. Miller / Bourns	FIXED IND 3.3UH 2A 80 MOHM SMD	0
PM1812-151J-RC J.W. Miller / Bourns	FIXED IND 150UH 105MA 9 OHM SMD	2675
SRR1208-681KL J.W. Miller / Bourns	FIXED IND 680UH 600MA 1 OHM SMD	0
SRP7050TA-5R6M J.W. Miller / Bourns	FIXED IND 5.6UH 6A 49 MOHM SMD	3105
1120-152K-RC J.W. Miller / Bourns	FIXED IND 1.5MH 800MA 1.26OHM TH	103
RL824-101K-RC J.W. Miller / Bourns	FIXED IND 100UH 1.02A 180MOHM TH	0
PM0805-68NK-RC J.W. Miller / Bourns	FIXED IND 68NH 500MA 270MOHM SMD	2713
CI160808-2N2D J.W. Miller / Bourns	FIXED IND 2.2NH 300MA 160MOHM SM	3286
PM105SB-221K-RC J.W. Miller / Bourns	FIXED IND 220UH 470MA 780MOHM SM	209
SDR6603-820M J.W. Miller / Bourns	FIXED IND 82UH 350MA 1.18OHM SMD	0
PM1608-1R0M-RC J.W. Miller / Bourns	FIXED IND 1UH 2.9A 50 MOHM SMD	0
RLB9012-150KL J.W. Miller / Bourns	FIXED IND 15UH 2.9A 56 MOHM TH	699
SRP7030CA-6R8M J.W. Miller / Bourns	FIXED IND 6.8UH 6.8A 42.5MOHM SM	1481
SRR7032-470M J.W. Miller / Bourns	FIXED IND 47UH 670MA 280MOHM SMD	1162
5800-270-RC J.W. Miller / Bourns	FIXED IND 27UH 1.5A 66 MOHM TH	663
PM5022-1R0M-RC J.W. Miller / Bourns	FIXED IND 1UH 10A 4 MOHM SMD	1190
CV201210-82NK J.W. Miller / Bourns	FIXED IND 82NH 300MA 200MOHM SMD	0
SRN2508A-R47M J.W. Miller / Bourns	FIXED IND 470NH 1.45A 80MOHM SMD	0
SDR0805-220MVL J.W. Miller / Bourns	FIXED IND 22UH 1.5A 110 MOHM SMD	0
SDR1806-100ML J.W. Miller / Bourns	FIXED IND 10UH 5.3A 25 MOHM SMD	969

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