DRV8311: 单MCU控制多路DRV8311P设计细节咨询

zongjin huang

Prodigy 30 points

Part Number: DRV8311

我现在用一个MCU驱动6个DRV8311P，使用tSPI的方式，分成两组，每个tSPI进行控制3个DRV8311P芯片驱动3个无刷电机。有以下几个疑惑的问题想请教一下：

1，DRV8311P内部输出的VDD（ LDO输出3.3V）是否支持直接连到一起，给整板其他器件（MCU,外接的Hall传感器，一般的逻辑芯片等）使用呢？

2，多个器件共用同一个SPI接口，为了改善信号质量，每个SPI的SCK,nCS,MOSI是否需要在DRV8311P端预留串阻呢？

3, DRV8311P的tSPI一对多的模式，layout走线上有什么需要注意的呢？比如拓扑结构是用菊花链还是走T点比较好呢？

4，DRV8311P的OUTA/B/C为了改善EMI性能，是否可以在输出端串接一个磁珠此举是否能改善EMI性能（接口后通过非屏蔽线连接到电机，线长约10cm，AWG24/awg26线缆）？或者有什么建议。

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 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.

2 年多前