Hi,
I am currently developing a product using a Piccolo TMS320F28027. I use the analog comparator module for over-current protection. The current is measured directly through a shunt resistor, referenced to the global ground. The voltage drop is connected to the ADC A2 pin via a resistor bridge, with no filtering whatsoever. This ADC input is only used for the over-current protection, and no SOC is ever performed on this pin.
When the over-current threshold is reached (comparison with DAC value), PWMs stop as expected, but the voltage on the ADC A2 pin drops , and keeps following the current in the shunt resistor, but with an offset. The voltage on this pin then "jumps" back to what it should be when the threshold is reached again.
Is there any particular current absorbed by the ADC A2 pin during the over-current protection ?
Best regards,
Adrien
