DRV8343-Q1: Passive OLD in independent MOSFET Mode

Hi Jass, 

What made the customer determine OLP isn't working?

Did the customer follow the steps included in the datasheet to perform a OLP diagnostic?

is EN_SHT_TST bit set high?

Regards,

Yara

Hi Yara,

They said they can realize this in 6 PWM mode, the steps maintain no changes.

They removed the cable and see if OLP is working. May you reproduce this in your lab using independent mode?

Thanks!

Hi Jass,

Are you saying that OLP is working in other modes just not independent mode? Does the customer have an evm they can test?

Regards,

Yara

Hi Yara,

They don't have EVM, but they have actual board using 8343 and OLD only not work in independent mode.

Hi Jass,

So open load detection should work in independent mode but there are certain scenarios where it wouldn't work.

Open load detection is not supported for high-side or low-side drivers (see below). 

Open load should work for solenoid configurations when using a HS+LS driver (see below) because there will be an active pullup and pulldown source on both sides of the solenoid. 

Is OLA and OLP not working or just one of then?

is short detection enabled?

Regards,

Yara

Hi Yara,

We just use 8343 to drive simple BLDC, we don't use OLA. Can you reproduce it in EVM?

Hi Jass,

Can you confirm whether short detection is enabled or not? It might take sometime before I can get in the lab with the EVM and test this myself, I will have an update early next week.

Regards,

Yara

Hi Yara,

Do you mean offline short diagnostic? If it is enable the same time as OLP, there will be some problem?

Hi Jass,

There will only be an issue if offline short diagnostic is disabled and a short is present, then OLP will not work.

offline short diagnostic and OLP use the same monitors but offline shorts takes precedent. However if offline shorts is disabled and a short is present then OLP will not be reported if it happens to be present at the same time.

Regards,

Yara

Hi Yara,

But I think this logic will work for both 6PWM and independent mos mode. Now only independent mos will have failure.

Hi Jass,

I reached out to some team mates for help on this. I found an EVM that I can test with but it looks like it is not configured for independent mode so I will have to send it for solder work. I'll update as soon as I can.

Regards,

Yara