User guide
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V 1.0.1
2021-01-27
REF-AIRCON-C302A-IM564 user guide
Air conditioner application reference design kits
System performance
The V
DC
sensing low-pass filter time constant is (R67+R68)*C34 = 21 k*10 nF = 210 µs, which is at least two times
the 40 kHz PFC PWM periods (25 µs for 40 kHz PFC) and higher than motor PWM periods (166 µs for 6 kHz motor
PWM); C34 can be adjusted to fit PFC voltage loop response.
Figure 37 shows the MCE firmware behavior of overvoltage protection (OVP):
Set OVP threshold to 2900 cts (set write register VdcOvLevel to 2900)
Start a Vac & Vdc trace with “Trigger on Fault” mode
Increase input AC voltage rapidly, the OV fault occurs when Vdc is over 2900 cts
Figure 37
OVP test by MCEDesigner trace function
