TIDT242 November 2022
2.4 EMI - Conducted Emissions
The conducted emissions are tested to be compliant with the CISPR 25 Class 5 standards. The CISPR 25 Class 5 compliance was achieved without a common-mode choke. Figure 2-10 through Figure 2-17 show the waveforms of the EMI test results at 13.5-V input.
where
- Peak: Peak Detection Result
- AVG: Average Detection Result
- PK: CISPR 25 Class 5 Peak Limits
- AV: CISPR 25 Class 5 Average Limits
Figure 2-10 EMI Performance, VPA_BUS = VPB_BUS = 5 V, IPA_BUS = IPB_BUS = 3 A, Positive Line
Figure 2-11 EMI Performance, VPA_BUS = VPB_BUS = 5 V, IPA_BUS = IPB_BUS = 3 A, Negative Line
Figure 2-12 EMI Performance, VPA_BUS = VPB_BUS = 9 V, IPA_BUS = IPB_BUS = 3 A, Positive Line
Figure 2-13 EMI Performance, VPA_BUS = VPB_BUS = 9 V, IPA_BUS = IPB_BUS = 3 A, Negative Line
Figure 2-14 EMI Performance, VPA_BUS = VPB_BUS = 15 V, IPA_BUS = IPB_BUS = 3 A, Positive Line
Figure 2-15 EMI Performance, VPA_BUS = VPB_BUS = 15 V, IPA_BUS = IPB_BUS = 3 A, Negative Line
Figure 2-16 EMI Performance, VPA_BUS = VPB_BUS = 20 V, IPA_BUS = IPB_BUS = 3 A, Positive Line
Figure 2-17 EMI Performance, VPA_BUS = VPB_BUS = 20 V, IPA_BUS = IPB_BUS = 3 A, Negative LineTable 2-2 shows the margin of each EMI test result.
Table 2-2 EMI Test Result Margins
| VIN (V) | VOUT (V) | Measurement Line | Margin (dB) |
|---|---|---|---|
13.5 | 5 | Positive line | 6.39 |
13.5 | 5 | Negative line | 9.84 |
13.5 | 9 | Positive line | 6.02 |
13.5 | 9 | Negative line | 6.56 |
13.5 | 15 | Positive line | 12.8 |
13.5 | 15 | Negative line | 12.63 |
13.5 | 20 | Positive line | 6.67 |
13.5 | 20 | Negative line | 7.21 |