DRV3901-Q1: VDRV questions

1) It is to block current back to PVDD from VREG (reservoir cap) in case of supply loss 

2) Depends on their FDTI

3) Yes, you can get a WD fault, SPI_err if something is wrong with the SPI. Please refer to the fault table for further queries on fault response. 

Best,

Keerthi

Hi Keerthi, 

Keerthivasan Kumanan said:

1) It is to block current back to PVDD from VREG (reservoir cap) in case of supply loss 

1) Not the diode between PVDD and VREG, I am asking the diode between VREG and VDRV. 

Keerthivasan Kumanan said:

2) Depends on their FDTI

2) How to determine if tWK_UP is sufficient for customer application? 

3) I find in the safety manual says it will be hardware trigger only. But is the hardware trigger method configurable? Or fix? Customer want to configure to deploy only with SPI command for normal state. 

Thanks!

Ethan Wen

Hi Ethan,

1) VREG to VDRV diode is required for the following reason:

2) you would need to know the fault tolerant time as I mentioned above and then figure out what the worst-case time is for running through all the diagnostics.  

3) Are you asking for the different ways to trigger?

who is the customer and what is their safety goal?

how many pyro fuses in system?

Best,

Keerthi

Hi Keerthi, 

I can share with your customer information through email. 

Keerthivasan Kumanan said:

Are you asking for the different ways to trigger?

For example, customer configure this register to SPI trigger only. So in normal state, customer deploy pyro-fuse through SPI command. When MCU fail(SPI communication fail), SPI trigger command is not available to send out. DRV3901-Q1 will detect SPI watchdog fault. Can DRV3901-Q1 change to HW trigger? If yes, how? 

Thanks!

Ethan Wen