DRV8243S-Q1LEVM: DRV8243S-Q1LEVM

Hi Anjali,

1. Can you check if >5 V is being provided to VM? 
2. Also, I assume you are using the DRV8243S-Q1LEVM. If this is true can you measure the SDO, SDI, nSCS, and SCLK pins to check if there is any activity on the SDO line or is it remaining low even after VM is provided >5 V and nSLEEP is pulled high?

Regards,

Joshua

Hi Joshua,

Thank you for your reply.

I checked the VM voltage. My motor operates at 24V. The measured voltage at VM is 23.7V, which is within the expected range.

As per your suggestion, I plotted the SPI communication signals and have attached a screengrab for your reference. You were right—I do not see any coming from the driver, even after pulling nSLEEP high.

Please review the attached images and let me know your thoughts.

Zooming in to the data signals:

Thank-you,

Anjali

Hi Anjali,

1. If you are using the DRV8243S-Q1LEVM can you try updating the firmware by opening the GUI go to File -> Program Device? https://dev.ti.com/gallery/view/MotorDriversBSM/DRV824x_DRV814x-Q1EVM-GUI/ver/1.0.2/
2. How many devices are having this issue?
3. Have you tried replacing this device with a known good device?

Regards,

Joshua

Hi Joshua,

We initially developed a motor driver PCB using the DRV8243SQDGQRQ1 IC, and it worked as intended. However, in the second revision of the same PCB, we are encountering the mentioned issue.

I have tested with two different driver ICs on the second revision PCB, and both exhibited the same problem. Unfortunately, we do not have an evaluation board for this IC.

Is there an alternative way to diagnose or resolve this issue? Below, I have attached the data signals plotted from the first version of the PCB, where everything functioned correctly. We are using the exact same code for the second revision.

Looking forward to your insights.

Best regards,

Anjali

Hi Joshua,

I replaced the IC with a known working IC, but the problem still persists.

Please find below the signals I plotted after changing the driver IC.

Zooming into the data signals.

Looking forward to your insights on this.

Best regards,

Anjali

Hi Anjali,

Thank you for preforming an ABA test, this seems to indicate the PCB is the leading cause of the issue and not the DRV8143S. Since you do see the nFAULT pin go high then low, this does indicate at power is getting to the VM pin correctly and the device is powering up properly.

1. It seems to me like the main issue is with the SPI traces themselves. If you have not already, can you measure the SPI signals as close to the DRV8243S as possible to check if the signals from the MCU are getting to the DRV8243S's SPI pins?
2. Between the PCB revisions were any changes made to the SPI lines which might be leading to this issue?

Regards,

Joshua

Hi Joshua,

Thank you for your reply.

1. I measured the SPI signals using the test points placed close to the driver IC, and I am confident that the signals from the MCU are reaching the driver IC.
2. There are some layout changes between the PCB revisions. We have added jumpers on the 4 SPI lines, but apart from that, there are no other modifications in the SPI connections. The jumpers are all properly connected, and I have also verified continuity of the 4 SPI signals from the MCU to the DRV using a multimeter before running the tests.

Is there a way to resolve this issue using hardware itself? Making layout changes and creating a third revision will take some time, so I would like to explore potential hardware solutions first.

Looking forward to your insights.

Best Regards,

Anjali

Hi Anjali,

1. Could you provide your schematic for this board? I will review it to see if there is anything there that may be causing this issue. 

2. Since you have jumpers on the SPI lines is it possible to use a different device to test the MCU and DRV8243 SPI communication using this jumper individually? This could help to narrow down if the issue is with the MCU side of the board or the DRV8243 side.

Regards,

Joshua

Hi Joshua,

1. PFB the schematic screenshots. 

2. It is possible to test the ICs individually. I will test them and let you know the results.

Thank-you,

Anjali

Hi Anjali,

Anjali Karmude said:

PFB the schematic screenshots. 

The schematic looks good, I do not see anything that could be causing this issue.

Regards,

Joshua