SNAA416A April   2025  – June 2025 LMK3C0105-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Test Setup
    1. 2.1 Board Variation Summary Table
    2. 2.2 Schematics
    3. 2.3 Layouts
    4. 2.4 Stack-Up
  6. 3CISPR-25
    1. 3.1 CISPR-25 Summary
    2. 3.2 CISPR-25 Results
      1. 3.2.1 Monopole
      2. 3.2.2 Bi-Conical
      3. 3.2.3 Log-Periodic
      4. 3.2.4 Horn
  7. 4CISPR-32
    1. 4.1 CISPR-32 Summary
    2. 4.2 CISPR-32 Results
  8. 5Summary
  9. 6References
  10. 7Revision History

3 CISPR-25

CISPR-25 is the Automotive standard for EMI. Four separate antennas are used to cover the 150kHz to 6GHz range.

Table 3-1 CISPR-25 Antenna Frequency Ranges
Antenna Frequency Range
Monopole 150kHz - 30MHz
Bi-Conical 30MHz - 200MHz
Log-Periodic 200MHz - 1GHz
Horn 1GHz - 6GHz

EMI spurs are measured in dBuV/m, with the antenna set 1m away from the center of the power supply line.

CISPR-25 limits are defined by certification class, with Class 1 being the least stringent, and Class 5 being the most stringent. All limits specified in this test report are Class 5.

Limits for maximum allowed EMI impact are specific to individual frequency bands. For example, TV Band 1 has a Class 5 Max Peak limit of 34dBuV/m, while Analogue UHF has a Class 5 Max Peak limit of 38dBuV/m.

Ground plane is shared between the conductive table and system.


CISPR-25 Setup Diagram

Figure 3-1 CISPR-25 Setup Diagram

CISPR-25 Chamber Setup

Figure 3-2 CISPR-25 Chamber Setup