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Original question:

DRV8718-Q1: why STATUS Registers shows twice in d/s

DRV8718-Q1: DRV8718 configuration

Elec Cheng
Expert 7055 points
Part Number: DRV8718-Q1

Hi Expert,

Our customer would like to use our DRV8718 and have some question.

1. how to configurate DRV8718 into four H-bridge? I read this e2e post but didn't get a clear view. To get four H-bridge, we can only configurate each half bridge as high side or low side, right? If so, how to control the speed and how to control the dead time? Do you have a guide for that?

2. You mention that PMW mapping. In four H-bridge configuration, if I want to drive four motor at the same time with different direction or speed, how to realize that? 

3. There is only two shunt amp. But if I wan to use four H-bridge and each has a shunt current sense, how to do with that? Thanks.

BR,

Elec Cheng

  • 0
    TI__Mastermind 37683 points

    Hi Elec,

    Elec Cheng said:
    You mention that PMW mapping. In four H-bridge configuration, if I want to drive four motor at the same time with different direction or speed, how to realize that?

    Each half-bridge can be mapped to a specific INx signal which is explained in section 8.3.3.1.2 in the datasheet. Essentially, IN1/IN2 can be used to control two H-bridges and IN3/IN4 the other two. 

    Elec Cheng said:
    how to configurate DRV8718 into four H-bridge? I read this e2e post but didn't get a clear view. To get four H-bridge, we can only configurate each half bridge as high side or low side, right? If so, how to control the speed and how to control the dead time? Do you have a guide for that?

    That is correct. the respective INx signals for each half-bridge forming the H-bridge are toggled at specific frequency and duty cycle to increase the speed of the motor. The device will add a handshake dead time automatically. https://e2e.ti.com/support/motor-drivers-group/motor-drivers/f/motor-drivers-forum/1006680/drv8718-q1-drv8718-q1-h-bridge-configuration-question

    Elec Cheng said:
    There is only two shunt amp. But if I wan to use four H-bridge and each has a shunt current sense, how to do with that? Thanks

    You can only use one amplifier for each half-bridge. Unless you multiplex one sense resistor for two h-bridges if only one of the h-bridges will be active at a time. otherwise, there is not enough amplifiers for all 4 h-bridges.

    Regards,

    Pablo Armet