DRV8662: About VDD voltage

Hi Jeff,

Thanks for the reply.
I understand.
This change is only for VDD, and if the input voltage of VDD is correct, the other pins will not be affected, right?

Sincerely.
Ryu

Hi Jeff,

Thanks for the reply.
Please tell me one more thing.
If I connect the power supply directly to PVDD without using a voltage multiplier circuit, is there any problem without connecting anything to VDD?
Or is there any problem even if a power supply like 3.0V is connected?

Sincerely.
Ryu

Hi Jeff,

Thanks for the reply.
Where will VDD be used?
And what kind of problems can be expected?
I would like to confirm if any design changes are necessary from the current circuit.

Sincerely.
Ryu

Hi Ryu,

I don't have immediate specifics but VDD powers all of the internal circuitry in the device except for the output driver which is powered by PVDD. If VDD is not correct and/or falls below 3.3V there's a significant possibility the entire part will shutdown. There isn't a situation where some of the part works and some if it doesn't. It's all or nothing. However there is no risk of damage to the part until you reach the absolute minimum of -0.3V. There's some percentage of parts that will work correctly with a 3.0V minimum but it's not reliable and I don't recommend depending on it for a design.  

Best regards,

Jeff McPherson

Hi Jeff,

Thanks for the reply.
Does the value of VDD when shutting down change over time or with changes in temperature?
Does it ever change with device-specific values?

Sincerely.
Ryu

Hi Ryu,

I don't know if we have that data but I will ask. Can you clarify what you mean by "change with device-specific values?"

Thank you,

Jeff McPherson

Hi Jeff,

Thanks for the reply.
 "change with device-specific values?" means due to lot differences.

Sincerely.
Ryu

Hi Ryu,

Understood. Unfortunately we don't have that kind of data. We only have a VDD sweep. Data over time is redundant, the failure is instantaneous. There is almost certainly some kind of trend with temperature but we don't have the data to know in which direction it goes. The failure rate with the original 3.0V min does vary lot-to-lot with a large swing. Sometimes lots passed with 80% average passing, others passed with only 7% average, meaning it's nearly impossible to predict which of your chips will survive a <3.3V min. The test program is set up to only let chips that verify 3.3V min pass so that's as far as we can guarantee. I hope that answers your questions; sorry for the limited data.

Best regards,

Jeff McPherson