Nanocrystalline cores

CMC (Common Mode Choke)

High-Permeability Nanocrystalline Cores For Automotive Filters

The Advanced Shield for Smart Vehicle Electronics

Engineered for extreme thermal stability and compact integration, our Common Mode Chokes (CMCs) provide the critical electromagnetic compatibility (EMC) required for the most demanding automotive ECUs, ADAS sensors, and high-speed communication bus systems.

Product Overview

CMC (Common Mode Choke) cores for automotive filters use reverse-wound coils on a single nanocrystalline core to effectively suppress EMI across a broad frequency range. During normal operation, opposing magnetic fields cancel out, allowing signal current to pass with minimal resistance, while common-mode noise generates high impedance for effective interference suppression. Compact, thermally stable, and highly efficient offering high permeability, low core loss, and reliable noise reduction.

Technical Specifications

Properties

Properties
	Nanocrystalline cores	Ferrite cores
Saturation magnetic induction Bs（T)	≥1.20T	0.4
Curie temperature（℃)	≥560	170
Saturation magnetism flexible coefficient（×10-6)	2	4
Operating Temperature Range	-55—130℃	80℃
Initial permeability　µ0	20000－160000	2000
Coercivity A/m	1.6	30

Specifications and Electrical Parameters

Test Conditions: 0.1V test signal, AL = Inductance for N=1 (Tolerance: +50% / –30%)

Specifications and electric parameters
Part No.	Core dimensions(mm) OD×ID×H	Finished dimensions(mm)			lFe (cm)	AFe (cm2)	AL※		Type of finish
Part No.	Core dimensions(mm) OD×ID×H	OD	ID	Ht	lFe (cm)	AFe (cm2)	10K nominal	100K nominal	Type of finish
1	7.2×4.5×3.0	8.0	3.5	4.5	1.81	0.03	12	--	Plastic case
2	9.8×6.5×4.5	11.2	5.1	5.7	2.56	0.06	22	5	Plastic case
3	10×6.5×5.0	11.2	5.1	6.5	2.59	0.07	24	--	Plastic case
4	12×8.0×4.5	13.5	6.5	6.5	3.14	0.07	25	--	Plastic case
5	14×10×5.0	15.5	8.5	6.8	3.77	0.08	21	--	Plastic case
6	16×10×8	17.2	8.5	10	4.08	0.19	40	--	Plastic case
7	20×12×8	22.3	10	10.3	5.03	0.25	45	--	Plastic case
8	20×12×8	22.3	22.3	10.3	5.03	0.25	20	9	Plastic case
9	16×12.5×6	≤17.8	≥10.7	≤8.0	4.48	0.08	16	5.3	Epoxy coated
10	26×16×10	27.5	14.0	12.5	6.60	0.39	65	15	Plastic case
11	21×16.5×12	22.8	14.6	15	5.89	0.21	--	7.5	Plastic case
12	28×18×15	30.2	16.0	17.6	7.23	0.59	60	--	Plastic case
13	25×20×10	27.8	18	12.7	7.07	0.20	30	7	Plastic case
14	30×20×15	33.1	17.8	17.5	7.85	0.59	70	--	Plastic case
15	32×20×10	34	17.8	12.5	8.17	0.47	45	--	Plastic case
16	40×25×10	42.5	22.5	13.0	10.21	0.59	50	--	Plastic case
17	40×25×15	43.2	21.9	18.9	10.21	0.88	70	--	Plastic case
18	40×32×15	44.3	29.2	18.6	11.31	0.47	45	7
19	40×32×15	≤43.5	≥28.5	≤17.8	11.31	0.47	14	7.2	Epoxy coated
20	50×32×15	53.2	29.0	18.2	12.88	1.05	60	--	Plastic case
21	50×32×20	53.2	29.5	23.5	12.88	1.40	80	--	Plastic case
22	50×40×20	≤53.5	≥36.5	≤22.8	14.14	0.78	30	10	Epoxy coated
23	50×40×25	53.4	36.2	28.3	14.14	0.98	62	12	Plastic case
24	60×40×20	63	37	24	15.71	1.56	70	--	Plastic case
25	64×40×20	67	37	24	16.34	1.87	80	--	Plastic case

Custom sizes available on request.

Key Features

High initial permeability and adjustable AL value (20,000–160,000)

Suitable for complex geometries and large production volumes

Excellent EMI suppression and wide frequency filtering

Free Cutting Brass Type I & II (IS 319 / BSS 249) + Custom AlloysFree Cutting Brass Type I & II (IS 319 / BSS 249) + Custom Alloys

High saturation flux density (≥1.20T) for compact choke design

CNC tolerance control for perfect alignment in plastic molding applications

Low core loss and small form factor with epoxy or plastic casing

Ideal for terminals, connectors, and grounding pins

High Curie temperature (≥560°C) and broad operating range (–55°C to 130°C)

Polished surfaces for better bonding and electrical contact

Corrosion Resistance

Suitable for use in humid or chemically exposed environments

Applications

Switched-mode power supplies (SMPS)

Common-mode noise suppression circuits

Automotive precision electronics

EMI harmonic filters for AC power grids

Single-phase and three-phase power line filters

General EMC applications across industries

Trust Reliability & Quality

With over 60 years of manufacturing excellence, PML delivers CMC for Automotive Filters trusted by OEMs and Tier 1 suppliers across sectors demanding robust performance.