I am now using a MCU to drive 6 DRV8311Ps and using tSPI to divide them into two groups. Each tSPI controls 3 DRV8311P chips to drive 3 brushless motors. I have the following questions to ask:
1. Does the internal LDO output VDD (LDO output 3.3V) of DRV8311P support direct connection together for use by other devices on the entire board (MCU, external Hall sensors, general logic chips, etc.)?
2. Multiple devices share the same SPI interface. In order to improve signal quality, do the SCK, nCS, and MOSI of each SPI need to reserve series resistance at each DRV8311P end?
3. What should be noted about the layout of DRV8311P's tSPI one-to-many mode? For example, is it better to use a daisy chain or a T-point in the topology structure?
4. In order to improve EMI performance, can a magnetic bead be connected in series at the output end of DRV8311P's OUTA/B/C? Can this improve EMI performance (after the interface, it is connected to the motor through unshielded wire, with a wire length of about 10cm, and an AWG24/awg26 cable)? Or what suggestions do you have.
