DRV8305-Q1: Absolute Maximum Ratings of PVDD-VDRAIN

Andrew,

Let me check and get back to you later today.

Regards,

-Adam

Andrew,

Could you explain your reasoning for needing this spec? What phenomenon are you safeguarding against?

Regards,

-Adam

Hi Adam

We are using drv8305q1 to design bldc control. In our design,the PVDD and VDRIAN pin is difference source same voltage 24V. when motor go to generator  mode, drv8305 is damaged. So,We connect PVDD and VDRAIN pin source together. But Still have a chance to break the DRV8305. We are finding the root cause.

Andrew,

Did you review this section in the DRV8305-Q1 datasheet: 9.1 Power Supply Consideration in Generator Mode

Regards,

-Adam

Hi Adam,

We have one condition to make PVDD=24V,

VDRAIN(Pin44) connect to 100ohm pin1 and 100 ohm pin2 short to 0V in a very short time (we use 2 different power sources,  one power for PVDD, another power for VDRAIN and motor MOSFET power)

And we find DRV8305-Q1 PVDD is short to ground , and dead forever in this condition.

We'd like to know if [DRV8305-Q1] DRV8305NQPHPRQ1 has the same "Voltage difference between supply and VDRAIN(PVDD-VDRAIN) +/-10V" spec as "DRV8305", 

and check if this is the damage root cause, 

Because we can not find this statement in "DRV8305-Q1" datasheet , but in "DRV8305" datasheet, thanks

BR,

Joseph

Joseph,

I don't understand your experiment: "VDRAIN(Pin44) connect to 100ohm pin1 and 100 ohm pin2 short to 0V in a very short time (we use 2 different power sources,  one power for PVDD, another power for VDRAIN and motor MOSFET power)"

This should be the same spec yes.

Regards,

-Adam

Hi Adam,
Thank for your information, just double confirm:
In conclusion, DRV8305-Q1 and DRV8305 both need to follow
"-10V < (Voltage difference between supply and VDRAIN(PVDD-VDRAIN)) <10V".
Otherwise, driver ic may damage.

It means we can not use PVDD=24V and let VDRAIN=0V, right?

BR,
Joseph