SLAU948B October 2024 – March 2025 MSPM0G3507
ADC configuration for three phase current sensing: The default pin configurations for ADC currents for three phase current sensing are shown in Table 2-12. The required connections are three ADC inputs connected to the three CSA outputs from the motor driver or external CSAs.
ADC0 and ADC1 are two simultaneous-sampling 4Msps analog-to-digital converters that are used to measure phase currents and voltages. ADC0 and ADC1 measure phase currents simultaneously and bus voltage sequentially depending on the rotor angle under normal motor run conditions.
An optional low-pass RC filter can be placed in series from the CSA outputs to the ADC inputs to filter out any high-frequency noise from the switching output signals for proper ADC sampling as shown in Figure 2-2.
Choose a filtering frequency fc that it at least 10 times the PWM switching frequency (fPWM). Use Equation 1 to calculate fc based on the RC filter design.
| MSPM0 Pin | Function | DRV Connection | DRV Function |
|---|---|---|---|
| A0_3 | ADC0, channel 3 input | SOA | Phase A current sense input |
| A0_2 | ADC0, channel 2 input | SOB | Phase B current sense input |
| A1_2 | ADC1, channel 2 input | SOB | Phase B current sense input |
| A1_1 | ADC1, channel 1 input | SOC | Phase C current sense input |
| MSPM0 Pin | Function | DRV Connection | DRV Function |
|---|---|---|---|
| A1_13 | ADC1, channel 13 input | SOA | Phase A current sense input |
| A1_14 | ADC1, channel 14 input | SOB | Phase B current sense input |
| A0_12 | ADC0, channel 12 input | SOB | Phase B current sense input |
| A0_2 | ADC0, channel 2 input | SOC | Phase C current sense input |
In single shunt current sensing either of ADC0/ADC1 is used to sample the same shunt current at two different instances in a single PWM cycle to estimate the three phase currents. User needs to configure appropriate ADC to sample the Current sense output from the Memory '0' index, Memory '1' Index for FOC operation. for details on ADC configurations for Single shunt current sensing, see the Sensored FOC User Guide.
| MSPM0 Pin | Function | Connection | Function |
|---|---|---|---|
| A1_13 | ADC 1, Channel 13 Input | Internal Amplifier in Buffer Mode | DC bus current sense |