DRV8718-Q1: BRG_CTRL1

Ivy Jin

Part Number: DRV8718-Q1

Tool/software:

Hi team,

My customer tests DRV8718-Q1 and meets the following issue, could you please help give some comments.

The customer writes all of the BRG_CTRL1 register to 0, but the GH1 and GH2 pins still have high voltage 13.5V. What is the reason for this?

Thank you!

Regards,

Ivy

4 months ago

0 Shinya Morita 4 months ago

TI__Mastermind 44375 points

Hi Ivy,

Thank you for your question. This is expected behaivior.

Please refer this Link.

(3) DRV8714-Q1: DRV8714-Q1 - Motor drivers forum - Motor drivers - TI E2E support forums

regards

Shinya

0 Ivy Jin 4 months ago in reply to Shinya Morita

TI__Expert 4505 points

Hi Shinya,

Thanks for your comments.

I see in this link is the recommendation that the SHx pin is pulled down to GND with a ~1Kohm resistance.

But my problem is that the GHx pins are showing high voltage in the HiZ state, how should GHx pin be handled?

Should the pull-down resistance be added to the GHx pin as well? Or if SHx is pulled down, GHx will also show low voltage?

Thanks.

Regards,

Ivy

0 Shinya Morita 4 months ago in reply to Ivy Jin

TI__Mastermind 44375 points

Hi Ivy,

Thank you for your reply.

>>this link is the recommendation that the SHx pin is pulled down to GND with a ~1Kohm resistance.

This link is not recommending pull down 1Kohm resistance.

In HiZ state, both external HS and LS FETs are OFF surely. However SH pin has weak pull up path, so SH shows ~PVDD voltage level, but HS FET is not turn on.

Bottom line is customer can just understand this is behaivior of weak pull up path. No need to worry it becuase HS FET is OFF surely.

regards

Shinya