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
4.3
Motor overcurrent protection (OCP) test
Figure 30 displays the OCP circuit for the IMC302A applications.
The output voltage of R83 & R77 divider is sensed by IMC302A’s internal comparators to achieve the overcurrent
protection function. The reference of the internal comparators is set by IMC302A’s internal DAC, and external
C36 is the LPF capacitor for DAC. MCEWizard calculates the DAC reference voltage based on the question input
of “Device Overcurrent trigger level setting for Comparator” and “Motor1 Current Input to ADC Offset Voltage.”
MCEWizard output parameter CompRef defines the DAC output voltage, which depends on the three items
listed below:
A: Expected overcurrent threshold
B: Gain of external current sensing network
C: Offset of the external op-amp or RC divider
Figure 30
Overcurrent protection circuit on the REF-AIRCON-C302A-IM564 reference design
