In this acquisition circuit, the voltage drop of the resistor SHUNT is measured when the lower bridge arm of the U-phase is turned on, and the value of the U-phase current can be calculated according to Ohm's law. When the upper bridge arm of the U-phase is on, the voltage drop of the resistor SHUNT is 0, but there is current in the U-phase. How do you know the U phase current value at this time? At this time, 0 has been collected as a feedback value to the ADC, and the phase current fed back by the ADC is 0, which is contrary to the actual situation