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UC3625: Newer device for 4th quadrant operation

Jacob Wyrick
Expert 8385 points
Part Number: UC3625

Hi team,

We're trying to design a system that can operate in 4th quadrant (iver speed & +ve torque) and use active braking.

We've looked at some devices like MCT8316, but we aren't able to add protection circuitry due to integrated FETs.

Are there any newer devices than the UC3625 that we can use for 4th quadrant operation?

Thanks,

Jacob

  • 0
    TI__Mastermind 18981 points

    Hi Jacob, 

    Can you let me know what the customer's other system requirements are? 

    Some general questions can be found in here: https://www.ti.com/lit/an/slvaes1a/slvaes1a.pdf

    Any background here on why they selected UC3625 device would be helpful to make a better recommendation.

    To do 4th-quadrant operation, do they have an external MCU handling the overall motor commutation by sending 6x/3x PWM inputs?

    Best Regards, 
    Andrew 

  • 0 in reply to Andrew Liu
    TI__Expert 8385 points

    Hi Andrew,

    You can find a lot of background on the conversation here: https://e2e.ti.com/support/motor-drivers-group/motor-drivers/f/motor-drivers-forum/1247496/mct8316z-sensored-bldc-motor-driver/4719067?tisearch=e2e-sitesearch&keymatch=subodh#4719067

    The selection of the UC3625 was because of the above thread.

    Thanks,

    Jacob

  • 0 in reply to Jacob Wyrick
    TI__Mastermind 18981 points

    Hi Jacob, 

    Thanks for linking us to context - I'll take a look at the request and try to get you a better response by end of the week.

    To be frank, we have very limited application support on the UCx625 series of devices within our group since they are very old and there is limited documentation - any documentation that exists is basically in the public datasheet itself. 

    I would advise that the customer migrates to an external MCU to handle motor control if the MCx/DRV10x products are not suitable for their needs. 

    Best Regards, 
    Andrew 

  • 0 in reply to Andrew Liu
    TI__Expert 8385 points

    Hi Andrew,

    Do we have any motor drive reference designs that can achieve 4th quadrant operation with regenerative braking using devices that're newer?

    Thanks,

    Jacob

  • +1 in reply to Jacob Wyrick
    TI__Mastermind 18981 points

    Hi Jacob, 

    On the DRV side of things, we don't really offer "quadrant" based control as part of the operation scheme. We instead offer the two options below in our portfolio today: 

    With DRV8x industrial/automotive devices, the customer can define this "quadrant" based control in their external MCU logic, and then just send the appropriate signals to our DRV8x which accepts 1x, 3x, or 6x "PWM" interface - meaning user has responsibility to determine what sequence of gates toggles will result in the "quadrant" operation they are looking for.

    With MCx or DRV10x devices, we offer a "SPEED/DIR/BRAKE" type of control interface, where the user decides the speed via PWM duty cycle, direction via a particular GPIO input, and a Brake input signal to turn off the MOSFETs and stop motor commutation. I am not sure how well quadrant-based operation translates SPEED/DIR/BRAKE, but that is a deeper "motor control theory" type of question that they'll have to resort to outside forums for support on. 

    In summary, the UCx625 devices have mention of "quadrant" based operation within its control logic but this type of control interface within our portfolio is unique to just that device. We have very limited support to offer on that device due to its uncommon interface and features, and we instead advise the customer to use a DRV8x or MCx device with external motor control technique resources to develop this quadrant-based operation in their external MCU motor control algorithm software. 

    Best Regards, 
    Andrew