DRV8800: Interval between nSLEEP high and PWM apply

Hi Goto,

Thanks for your question.

DRV8800 uses charge pump to  generate a supply above VBB to drive the source-side DMOS gates. The 1ms time is given to stabilize the charge pump. This is needed for the turning ON of the DMOS FETs.

Thanks,

Ibinu

HI Ibinu,

Thank you for answer.

So, in the case below, does the charge pump stabilize gradually?
Or will the motor not run until nSLEEP reconfiguration?

>nSLEEP released
>(Wait<1msec)
>Through-up (PWM0% to 80%, 23.4kHz, 20msec)
>Constant speed (PWM80%, 23.4 kHz)
>Slew down (PWM80% -> 0%, 23.4kHz, 20msec)
>Nsleep setting  ←Does the motor not move until this time? 

If you have any question, please let me know.

Best regards,
Goto

HI Ibinu,

Is there any update?

Goto

Hi Goto,

Thanks for the follow up.

While the charge pump is stabilizing if the device is trying to run the motor, the charge pump might not rise to the required level. The VCP voltage level is internally monitored and, in the case of a fault condition, the outputs of the device are disabled.

Please let me know if this clarifies.

Thanks,

Ibinu

Hi Ibinu,

Thank you for reply.

i.e. if I input PMW without 1ms delay, VCP will not stabilize and the motor may never start, right?

Best regards,

Goto 

Hi Ibinu,

Do you have any update?
If you have any question, please let me know.

Best regards,
Goto