DRV8889-Q1: SDO level fall

Colt Zhang

Expert 5045 points

Part Number: DRV8889-Q1

hi Team，

In the DRV8889 SPI test wave, the SDO waveform is abnormal, please see why this amplitude has dropped.

SDO scope is abnormal:

clock is normal:

SDI is normal:

over 1 year ago

0 Ryan Kehr over 1 year ago

TI__Guru 55615 points

Colt,

Can you please plot SCLK/SDI/SDO/nSCS on the same scope capture?

SDO will go to HIZ state on a nSCS = HIGH state per figure 7-32 in the datasheet.

Regards,

Ryan

0 Colt Zhang over 1 year ago in reply to Ryan Kehr

TI__Expert 5045 points

hi Ryan,

pls see the test scope.

0 Ryan Kehr over 1 year ago in reply to Colt Zhang

TI__Guru 55615 points

Colt,

Device is working as expected. When nSCS = HIGH, the SDO output will be HIZ state. In HIZ, output is not driven and will float at an indeterminate voltage.

There is no issue.

Regards,

Ryan

Motor drivers

Motor drivers forum

DRV8889-Q1: SDO level fall