Examples of actions taken to comply with the CISPR25 standard governing radio emissions (noise emitted) from devices mounted in vehicles

EMI Suppression Filters (EMC and Noise Suppression)Examples of measures to suppress noise in USB 2.0 mode CISPR25 Class 5 signal lines

Details of noise suppression measures taken in USB 2.0 mode

When interfaces compliant with the USB 3.0 standard are to be operated as equivalent to the USB 2.0 standard, signal lines used for USB 2.0 are used. As USB 2.0 signal lines have both transmission (TX) and reception (RX) functions, common mode choke coils are inserted into these lines.

Examples of actions taken to comply with the CISPR25 standard governing radio emissions (noise emitted) from devices mounted in vehicles

Common mode choke coil in TX/RX line
DLM11SN900HZ2
or
DLW21SZ900HQ2
inserted

Click here Open in New Window  for details of the measurement conditions.

Noise measurement results (for measures to suppress noise in USB 2.0 signal lines)

DLM11SN900HZ2 used

Examples of actions taken to comply with the CISPR25 standard governing radio emissions (noise emitted) from devices mounted in vehicles
  • Examples of actions taken to comply with the CISPR25 standard governing radio emissions (noise emitted) from devices mounted in vehiclesBy adding a common mode choke coil (DLM11SN900HZ2), the noise was successfully reduced(maximum reduction of approx. 37 dB at a vertically polarized wave frequency of 240 MHz).

DLW21SZ900HQ2 used

Examples of actions taken to comply with the CISPR25 standard governing radio emissions (noise emitted) from devices mounted in vehicles
  • Examples of actions taken to comply with the CISPR25 standard governing radio emissions (noise emitted) from devices mounted in vehiclesBy adding a common mode choke coil (DLW21SZ900HQ2), the noise was successfully reduced(maximum reduction of approx. 37 dB at a vertically polarized wave frequency of 240 MHz).

Verification of SI compatibility when filters are inserted

USB2.0 Eye Diagram near

  • 車載機器の雑音規格CISPR25対策例

    short

  • 車載機器の雑音規格CISPR25対策例

    DLM11SN900HZ2

  • 車載機器の雑音規格CISPR25対策例

    DLW21SZ900HQ2

USB2.0 Eye Diagram far

  • 車載機器の雑音規格CISPR25対策例

    short

  • 車載機器の雑音規格CISPR25対策例

    DLM11SN900HZ2

  • 車載機器の雑音規格CISPR25対策例

    DLW21SZ900HQ2

<Measures to suppress noise in signal lines>