• State Resolved
  • Locked Locked
  • Replies 4 replies
  • Subscribers 31 subscribers
  • Views 2720 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.

DRV8312/8332 - PWM A/B/C sequence

Jordda
Intellectual 665 points
Other Parts Discussed in Thread: DRV8312, DRV8332

Hi,

I've read the datasheet of DRV8312/8332 and had some questions regarding to PWM A/B/C (page 16). For BLDC motor control by 6 MOSFETs, generally there are only 2 MOSFETs (one upper-side and one low-side MOSFETs) turned ON to drive motor. But I found DRV8312/8332 seems to turn 3 MOSFETs. Foe example, Q1(upper-side of A), Q4(low-side of B) and Q6(low-side of C) are turned ON. What's the difference between 2 and 3 MOSFETs turn ON for driving motor?? Or what advantages can be utilized in 3 MOSFETs configuration?? Thanks for support.

  • 0
    TI__Mastermind 26065 points

    Hi Jordda

    Do you mean in Page 16, in S1 state, PWM_A = 1, PWM_B = 0, PWM_C = 0 ？

    Please note that PESETn_C = 0 at S1 state, so, bridge C is still HiZ, the current only goes on Phase A and B, only 2 MOSFET open.

    Thanks.

    Wilson

    Motor Application Team

  • 0 in reply to Wilson Zuo
    Prodigy 10 points

    Good morning !
    I ordered and received a DRV8332 driver but fail to spin a stepper motor.
    The motor is a SIEMENS 1BS1845-4TA; A picture of him is available at link:
    http://www.topkapibilgisayar.com/Siemens-1BS1845-4TA-V22411-S-D2-Nr-733.30001-27-Motor

    From the motor go out three wire.
    For that the motor to spin every single wire must be connected
    to +Vcc, ground or leave unconnected as shown in the picture 01.
    In order to obtain those waveforms at the output of the DRV8332 driver,
    command sequences, according to datasheet, should be those outlined
    in the picture 02 ?
    Pin numbering is according to the picture 03 ?
    That minimum PWM switching frequencies of 10 kHz (maximum 500 kHz)
    is the one that corresponds to the circled areas in picture 04 ?
    The waveforms controlling the DRV8332 (except the reset signals) consist
    of a low frequency PWM whose levels are generated by a high frequency PWM ?
    And if so, the low frequency PWM is the one that make the motor running
    step by step and the high frequency PWM is that minimum 10 kHz signal?
    Which is the slowest PWM signal that DRV8332 can generate such that
    the motor spins at low speed ?
    All pictures referred to are downloadable at link:
    http://www.filedropper.com/pictures_17
    If I have not sent this message to the right place I apologize and
    I kindly ask you to guide me !
    Thanks for your time !

  • 0 in reply to biticu_mihai
    TI__Guru** 114905 points

    Hi Mihai,

    Can you provide more details?

    Is the motor really a stepper motor? Do you have a datasheet for this motor which contains the specifications and how to drive the motor?

    How are you controlling the DRV8332?

    Thank you.