Powering the TI DRV593

Rob Lawrence

Other Parts Discussed in Thread: DRV593

Hi,

I am using the DRV593 in a client's project. Will I damage the device if I power AVDD from 3.3v and PVDD from 5v? I do not see that this will violate any limits in the data sheet, but all of the examples I have seen always power these from the same voltage. Is it OK to power these from separate supplies?

Similarily, if there is an offset voltage between AGND and PGND, will this cause a problem? In my design, AGND and PGND are tied together off board at the power supply. Is this ok to do? How great could an offset between these GNDs be, and not be an issue?

Thanks,

Rob

over 13 years ago

0 Don Dapkus over 13 years ago

TI__Guru**** 189401 points

Hi, Rob,

Sorry for the delay, we overlooked your post.

AVDD and PVDD must be within a diode drop of each other, as must AGND and PGND otherwise BAAAAAD things happen (like letting out the magic smoke...)

-d2

0 JONATHAN GRAHAM98068 over 13 years ago in reply to Don Dapkus

Prodigy 90 points

Related question, If the DRV593 is in a different power domain than the IC driving it's inputs, what's the allowable current thru its input pins when the device is not powered? I'm assuming at least 10's of uA to generally be safe, but can I get away with 4mA through those pins without damaging anything?

0 Don Dapkus over 13 years ago in reply to JONATHAN GRAHAM98068

TI__Guru**** 189401 points

Jonathan,

That's probably not a good idea. You will basically forcing a dc current thru our ESD cells which are not designed for that. And, you migth find all kinds of strange things happen due to the internal connections of the ESD cells.

-d2

0 JONATHAN GRAHAM98068 over 13 years ago in reply to Don Dapkus

Prodigy 90 points

Don,

Thanks, but do you have a ballpark number on what those ESD cells can handle? (1nA?, 10nA? 100nA? 1uA? 10uA? 100uA?) I'm not trying "use" the part in this mode, just avoid damaging the interior of it during a power supply failure situation.

Thanks,

-Jonathan

0 Don Dapkus over 13 years ago in reply to JONATHAN GRAHAM98068

TI__Guru**** 189401 points

Jonathan,

I don't, but usually 10-100 uA is okay, I'd say... The problem is they are not designed for dc operation, they are designed to protect against super short duration ESD spikes.

-d2