DRV8353R: Unused pin

Brian Wang0928

Part Number: DRV8353R

Hello team,

There're two questions about DRV8353RS in e-scooter application.

1. There're only two current senses of U and V phase being used and the W phase can be calculated by MCU. How to deal with unused pin of the SPC, SNC and SOC? Can one of current measurement phases be disabled by SPI register?

2. On bench testing, customer found when OC event is happened and nFAULT is activated, all LOW side MOSFETs are turned ON. Why all gate drivers are not disabled after OC event is triggered?

Regards

Brian

over 1 year ago

0 Yara Al Shami over 1 year ago

TI__Genius 15125 points

Hi Brian,

Brian Wang0928 said:
2. On bench testing, customer found when OC event is happened and nFAULT is activated, all LOW side MOSFETs are turned ON. Why all gate drivers are not disabled after OC event is triggered?

I Believe this question is answered in the FAQ: https://e2e.ti.com/support/motor-drivers-group/motor-drivers/f/motor-drivers-forum/1176539/faq-quick-guide-to-debugging-common-issues-in-bldc-motor-drivers

Brian Wang0928 said:
2. On bench testing, customer found when OC event is happened and nFAULT is activated, all LOW side MOSFETs are turned ON. Why all gate drivers are not disabled after OC event is triggered?

Is the customer using the SPI or Hardware version?

Regards,

Yara

0 Brian Wang0928 over 1 year ago in reply to Yara Al Shami

TI__Genius 14050 points

Hello Yara,

Thanks.

Q1: We didn't find the related answers on the link you posted. Could you help to answer it if possible!

Q2: The SPI version is been using now.

Regards

Brian

0 Yara Al Shami over 1 year ago in reply to Brian Wang0928

TI__Genius 15125 points

Hi Brian,

Give me a day to look into this then and give you an update

Thanks,

Yara

+1 Yara Al Shami over 1 year ago in reply to Yara Al Shami

TI__Genius 15125 points

Hi Brian,

For your first question, I believe this should help

Brian Wang0928 said:
2. On bench testing, customer found when OC event is happened and nFAULT is activated, all LOW side MOSFETs are turned ON. Why all gate drivers are not disabled after OC event is triggered?

What does your customer have OCP_MODE set to?

Regards,

Yara

0 Brian Wang0928 over 1 year ago in reply to Yara Al Shami

TI__Genius 14050 points

Thanks.

Be honest, customer doesn't know what mode was set since RD is doing benchmarking from other branding product.

Which one of Mode could cause the similar behavior i describe as previous thread?

Regards

Brian W

0 Yara Al Shami over 1 year ago in reply to Brian Wang0928

TI__Genius 15125 points

Hello Brian,

It would either have to be that it is completely disabled (OCP_MODE = 11b) or you have it set to Report Only (OCP_MODE = 10b). You should be able to read the register and see what it is set to.

Regards,

Yara

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DRV8353R: Unused pin