• State Resolved
  • Replies 4 replies
  • Subscribers 29 subscribers
  • Views 118 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

DRV8305: Using only GLA to GLC as gate signals

Hiroki Sakaguchi
Prodigy 150 points
Part Number: DRV8305
Other Parts Discussed in Thread: DRV8313, DRV8323R, DRV8301

Tool/software:

I would like to ask about the use of the DRV8305.
We would like to use this motor driver to implement a 3-phase unipolar drive.
Therefore, in 6-PWM mode, we are thinking of dropping the high side (INHA, INHB, INHC) to ground and sending signals from the MCU to the low side (INLA, INLB, INLC) to operate only the low side gates (GLA, GLB, GLC).
The input signal is not PWM, but a signal that is generated from Hall IC signals and switches every 120° of the armature angle.
Is this kind of usage feasible?

  • 0
    TI__Expert 7295 points

    Hi Hiroki,

    This isn't something I have seen before unfortunately. I will have to consult my team to see what they recommend. I'll have an update by the end of the week.

    Regards,

    Yara

  • 0 in reply to Yara Al Shami
    Prodigy 150 points

    Hi Yara,

    Thank you for your consideration.
    I know this is an unexpected use, but I hope you will consider it.
    I look forward to your response.

    Sincerely yours,

    Hiroki

  • 0 in reply to Hiroki Sakaguchi
    TI__Expert 7295 points

    Hi Hiroki,

    I'm still looking into this, expect an update by the end of the week.

    Regards,

    Yara

  • +1 in reply to Yara Al Shami
    TI__Expert 7295 points

    Hi Hiroki,

    The DRV8305 is designed for full 3-phase control therefore using the DRV8305 this way is not recommended. Here some things to consider:


    1. The DRV8305 has built-in fault protections that expect proper operation of both high-side and low-side drivers. Grounding the high-side FETs might trigger some fault detection mechanisms like overcurrent or gate faults. This would require either disabling certain protections or ensuring they are not triggered in your specific configuration.

    2. Even though you’re only driving the low-side FETs, there might still be interactions with the high-side driver circuitry when it comes to gate drive current and timing parameters (like dead time).

    I'm still unsure about what device might actually suit your application and whether it would work or not as it is quite unique but I would recommend looking into the following:


    DRV8313: Best for simple, low-power applications where you need control over just the low-side FETs.
    DRV8323R: Best for applications where you need flexibility and more advanced diagnostics and control but still want an easier time disabling high-side drivers.
    DRV8301/02: Suitable for high-power applications with external MOSFETs and custom configurations, though it might be more complex to work with.

    Regards,

    Yara