• State Resolved
  • Locked Locked
  • Replies 5 replies
  • Subscribers 31 subscribers
  • Views 655 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

DRV8306: Current Limit function

Hirotaka Matsumoto
Guru 27595 points

Part Number: DRV8306
Other Parts Discussed in Thread: DRV8350, , DRV8353

Hi all

Would you mind if we DRV8350?

DRV8306 has current limitation function.
However, DRV8350 doesn't have current limitation function.
Why does DRV8306 have this function?

And then, most of BLDC driver does't have current limitation function because BLDC doesn't require precise current control(like as stepping motor).

Kind regards,

Hirotaka Matsumoto

  • 0
    TI__Guru 66550 points

    Hirotaka-San,

    Thanks for posting on the Motor Drives Forum.

    The DRV8350 does have current limiting function, it is the VDS protection feature. If more accurate current limiting is needed then the DRV8353 would be better since it includes three LS current shunt amps.

    Regards,

    -Adam

  • 0 in reply to Adam Sidelsky
    Guru 27595 points

    Adam san

    Thank you so much for your copperation always!

    We have additional question.
    We assume that VDS protection feature is OCP.

    Most of BLDC drivers don't have Current limitation(Itrip) function.
    So, BLDC doesn't require to use precise current control compared with stepper drivers, right?

    Kind regards,

    Hirotaka Matsumoto

  • 0 in reply to Hirotaka Matsumoto
    TI__Guru 66550 points

    Matsumoto-San,

    We have two protection features available, VDS_OCP and SEN_OCP.

    Most of our drivers have overcurrent protection. Some of them do not have CSA and therefore they can only support VDS_OCP protection. The limitation of this feature is that the customer can set only the VDS limit but it does not allow them to measure the current, only the VDS limit that will trigger an overcurrent event.

    Some of the drivers have VDS protection and CSA which gives them also SEN_OCP. SEN_OCP allows the customer to set a second OCP level and use the sense resistor to measure the current through the bridge.

    You are correct that we do not always require precise current control for methods such as Trapeziodal control but some control schemes require very accurate current control or BEMF sensing so we have CSA available.

    Regards,

    -Adam

  • 0 in reply to Adam Sidelsky
    Guru 27595 points

    Adam san

    Thank you so much for your reply!

    DRV8306 : VDS_OCP, VSEN_OCP, PWM Limiter -> This device has OCP and current limitation(PWM limit).
    DRV8350 : VDS_OCP, CSA -> This device has OCP only. If PWM limit requires, we have to use CSA(amplifier) output.
    ※ DRV8350 has VSEN_OCP however it is for half bridge.

    Is our recognition correct?

    Kind regards,

    Hirotaka Matsumoto

  • 0 in reply to Hirotaka Matsumoto
    TI__Guru 66550 points

    Matsumoto-San,

    Only the DRV8353 has SEN_OCP because it has the triple CSA included, the DRV8350 does not include the triple CSA needed for this feature.

    Regards,

    -Adam