Noise suppression technologies/case study introduction (Automotive)

For automotive LANs Suppression of noise in CANs using common mode choke coils (2) Radiated noise evaluation

■Evaluation system

Measurement frequencies :  150 kHz to 1 GHz
Test standard : CISPR25 Ed.3 (150 kHz to 1 GHz)
DUT : CAN transceiver (made by company A)
Evaluation items : Common mode choke coils  (DLW43SH510XK2)
for automotive LANs Suppression of noise in CANs using common mode choke coils

Radiated noise evaluation / Table of equipment used

■Evaluation results No filter used, 250 kHz pulses

for automotive LANs Suppression of noise in CANs using common mode choke coils
for automotive LANs Suppression of noise in CANs using common mode choke coils

■Evaluation results DLW43SH510XK2 used, 250 kHz pulses

for automotive LANs Suppression of noise in CANs using common mode choke coils
for automotive LANs Suppression of noise in CANs using common mode choke coils

A noise-suppression effect was achieved by adding the DLW43SH510XK2.
(Noise was reduced by 25.1 dB at a 20.5 MHz vertical polarized wave frequency.)

■Evaluation results No filter used, 500 kHz pulses

for automotive LANs Suppression of noise in CANs using common mode choke coils
for automotive LANs Suppression of noise in CANs using common mode choke coils

■Evaluation results DLW43SH510XK2 used, 500 kHz pulses

for automotive LANs Suppression of noise in CANs using common mode choke coils
for automotive LANs Suppression of noise in CANs using common mode choke coils

By adding the DLW43SH510XK2, a noise-suppression effect was achieved.
(Noise was reduced by 17.8 dB at a 21.0 MHz vertical polarized wave frequency.)

Summary of radiated noise evaluation effects

■250 kHz pulses

When no filter was used, a high level of noise was found from 150 kHz to 30 MHz. 
By adding choke coil DLW43SH series, a noise-suppression effect was achieved.

The DLW43SH series achieved a noise-suppression effect of approx. 26 dB at a 20.5 MHz vertical polarized wave frequency.

■500 kHz pulses

When no filter was used, a high level of noise was found from 150 kHz to 30 MHz. 
By adding choke coil DLW43SH series, a noise-suppression effect was achieved.
A noise-suppression effect of approx. 18 dB at a 21.0 MHz vertical polarized wave frequency was achieved.

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