DRV8243-Q1: SDO line issue

Hi Nijith,

Thank you for your question. If possible, could you please share a little information about your system to give us a better understanding of your issue. 

1. What is the load configuration you are trying to drive (HS, LS, full-bridge)?

2. What type of probe are you using (tip and barrel, ground loop, etc.)?

3. Could you please send a picture of your layout?

Best,

David

Hi Nijith,

The SDO pin on the DRV8243P-Q1 is a push-pull output. The output logic high will be same as DVDD input, like you mentioned 5V. Do you have a series resistor between this pin and SDI of the MCU? Does the MCU support 5V I/O logic for the SPI port? 

Could you please elaborate on this? "When i probe my DSO with  SPI lines (SCLK,SDO,SDI), motor runs. If i remove the probe, SPI communication fails.". Do you have SPI waveforms captured that you can share with us? Do all these pins have series resistors between the MCU and driver. If yes what are the values?

"But even i touch the SDO line with open probe, motor runs.".  Does this mean the motor spins with no inputs applied to EN or PH pins? Are these pins held low. Are you enabling SPI control for these two inputs?

Regards, Murugavel