Nanocrystalline EMI Filter Cores
Our nanocrystalline cores maintain high impedance even at elevated temperatures, preventing saturation in high-current industrial power supplies where traditional ferrite cores often fail. Engineered for CISPR 25 and EN 55011 compliance.
Reviewed by: Rajesh Kumar, Senior Magnetics Engineer | 15+ years in power electronics design
EMI Filter Applications
- • Switch Mode Power Supplies
- • Motor Drive Inverters
- • Solar Inverters
- • LED Drivers
Behind the Design: Material Selection for EMI Suppression
Our engineering team selected nanocrystalline over Mn-Zn ferrite for EMI applications based on three critical factors: higher saturation induction (1.2T vs 0.4T) prevents core saturation under fault currents, superior permeability (30,000-100,000 vs 2,000-15,000) provides better noise suppression, and stable performance up to 120°C eliminates thermal derating in industrial environments.
Material Comparison for EMI Filter Cores
| Material | Permeability (μ) | Saturation (Bs) | Temp Range | Best For |
|---|---|---|---|---|
| Nanocrystalline | 30,000-100,000 | 1.2T | -40°C to +120°C | High-power SMPS, EV chargers |
| Mn-Zn Ferrite | 2,000-15,000 | 0.4T | -40°C to +100°C | Low-power applications |
| Ni-Zn Ferrite | 500-2,000 | 0.35T | -40°C to +125°C | High-frequency (>1MHz) |
Case Study: 50kW Solar Inverter EMC Compliance
Successfully implemented in a 50kW solar inverter project to meet Class B emissions requirements where standard ferrite cores were overheating at 85°C ambient temperature. Our nanocrystalline cores maintained stable impedance characteristics, reducing conducted emissions by 15dB at critical frequencies (150kHz-30MHz) and achieving CISPR 11 compliance.
Challenge
Ferrite cores saturating at high ambient temperatures
Solution
Nanocrystalline cores with 1.2T saturation
Result
15dB improvement, CISPR 11 compliance achieved
EMI Core Selector Tool
Select Core Based on Your Requirements
Recommended: CC-NC-CMC-005-40 - Optimal for 15-25mm cables in VFD applications with superior temperature stability.
Compliance Standards & Requirements
| Standard | Application | Frequency Range |
|---|---|---|
| CISPR 25 | Automotive EMC | 150kHz-108MHz |
| EN 55011 | Industrial Equipment | 150kHz-1GHz |
| IEC 61000-6-3 | Residential/Commercial | 150kHz-1GHz |
| FCC Part 15 | Computing Equipment | 150kHz-1GHz |
| MIL-STD-461 | Military/Aerospace | 10kHz-18GHz |
Insertion Loss Performance: Common Mode vs Differential Mode
Insertion Loss (dB) vs Frequency (MHz) showing superior common-mode suppression (>40dB at 150kHz) while maintaining low differential-mode impedance (<10Ω).
Technical Specifications for EMI Filter Cores
Our nanocrystalline EMI filter cores are optimized for common-mode choke applications in power electronics, providing superior EMI suppression performance.
| Parameter | Value | Engineering Note |
|---|---|---|
| Frequency Range | 10kHz - 1MHz | Optimized for switching frequencies |
| Permeability (μ) | 30,000 - 100,000 | Temperature stable |
| Saturation Induction (Bs) | 1.2T | Prevents saturation under fault currents |
| Operating Temperature | -40°C to +120°C | Automotive grade |
| Core Loss @ 100kHz | <150 mW/cm³ | Low heating in continuous operation |
| Curie Temperature | 570°C | Thermal stability margin |
Typical Applications
- • Variable Frequency Drives (VFDs) - 5-500kW
- • EV Charging Stations - Level 2 & DC Fast
- • Medical Imaging Equipment - MRI, CT scanners
- • High-Speed Rail Traction Systems
- • Industrial Welding Equipment
Download: Complete Technical Datasheet (PDF)
EMI Filter Applications
Common-Mode Choke Design
Design Considerations:
- • High common-mode impedance (>1kΩ at 100kHz)
- • Low differential-mode impedance (<10Ω)
- • Balanced winding for optimal performance
- • Minimal leakage inductance
Advantages over Ferrite:
- • Higher saturation prevents core saturation
- • Better temperature stability
- • Lower core losses at high frequencies
- • Smaller core size for same performance
Available EMI Filter Core Products
Complete range of nanocrystalline common mode choke cores for EMI suppression
| Core Code | Bare Core Size (mm) | Cased Size (mm) | Material | μi (typ) | AL (nH/N²) | Typical Line Current | Notes / Main Use |
|---|---|---|---|---|---|---|---|
| CC-NC-CMC-001-20 | 20×12×8 | 22.6×10.6×10 | Nanocrystalline | 80k-90k | Min 80k μi, AL=>60 | 5-15A | SMPS, small drives |
| CC-NC-CMC-002-25 | 25×16×10 | 27.5×13.8×12.6 | Nanocrystalline | 80k-90k | Min 80k μi, AL=>65 | 5-15A | SMPS, small drives |
| CC-NC-CMC-003-30A | 30×18×10 | 33×16.4×13.2 | Nanocrystalline | 80k-90k | Min 90k μi, AL=>59 | 10-30A | Industrial drives, EV chargers |
| CC-NC-CMC-004-30B | 30×20×15 | 33.6×17.7×17.8 | Nanocrystalline | 80k-90k | Min 90k μi, AL=>88 | 10-30A | Industrial drives, EV chargers |
| CC-NC-CMC-005-40 | 40×25×15 | 44.2×21.6×18.9 | Nanocrystalline | 80k-90k | Min 90k μi, AL=>100 | 30-80A | Solar inverters, high volume |
| CC-NC-CMC-006-40L | 40×32×15 | 43×29×18.8 | Nanocrystalline | 80k-90k | Min 90k μi, AL=>47 | 30-80A | Industrial drives, EV chargers |
CC-NC-CMC-001-20
20×12×8 mm
22.6×10.6×10 mm
80k-90k μi
Min 80k μi, AL=>60
CC-NC-CMC-002-25
25×16×10 mm
27.5×13.8×12.6 mm
80k-90k μi
Min 80k μi, AL=>65
CC-NC-CMC-003-30A
30×18×10 mm
33×16.4×13.2 mm
80k-90k μi
Min 90k μi, AL=>59
CC-NC-CMC-004-30B
30×20×15 mm
33.6×17.7×17.8 mm
80k-90k μi
Min 90k μi, AL=>88
CC-NC-CMC-005-40
40×25×15 mm
44.2×21.6×18.9 mm
80k-90k μi
Min 90k μi, AL=>100
CC-NC-CMC-006-40L
40×32×15 mm
43×29×18.8 mm
80k-90k μi
Min 90k μi, AL=>47
Technical Resources
📖 Technical Article: Nanocrystalline vs Ferrite for EMI Filters
Detailed technical comparison covering performance differences, frequency response, and application guidelines.
Read Technical ArticleFrequently Asked Questions
How to reduce conducted emissions in EV charging stations?
EV chargers generate high-frequency switching noise (20-100kHz) that requires common-mode chokes with high impedance at these frequencies. Our nanocrystalline cores provide >1kΩ impedance at 100kHz while maintaining thermal stability up to 120°C, critical for outdoor charging stations. The 1.2T saturation prevents core saturation during ground fault conditions.
Nanocrystalline vs Ferrite for common mode chokes - which performs better?
Nanocrystalline cores outperform ferrite in three key areas: (1) Higher saturation (1.2T vs 0.4T) prevents saturation under fault currents, (2) Superior permeability (30,000-100,000 vs 2,000-15,000) provides better noise suppression with fewer turns, (3) Stable performance to 120°C eliminates thermal derating required with ferrite cores above 80°C.
Compliance with CISPR 25 and EN 55011 - what core specifications are needed?
CISPR 25 (automotive) requires suppression from 150kHz-108MHz, while EN 55011 (industrial) covers 150kHz-1GHz. Our cores provide >40dB common-mode suppression at 150kHz with stable performance across temperature. The key is maintaining high impedance at the critical 150kHz-30MHz range where most EMC failures occur.
What causes core saturation in EMI filters and how to prevent it?
Core saturation occurs when differential currents (load imbalance or fault conditions) exceed the core's saturation limit. Traditional ferrite cores saturate at 0.4T, while our nanocrystalline cores handle 1.2T - a 3x improvement. This prevents filter failure during ground faults or load imbalances common in industrial applications.
Custom EMI Filter Core Design
Our magnetics engineers design nanocrystalline cores for specific EMI suppression requirements. From prototype to production, we optimize core geometry for your exact impedance and thermal specifications.