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BLDC better motor driver needed

Christian Ahler
Prodigy 130 points
Other Parts Discussed in Thread: DRV8312, DRV832X, DRV8307, DRV8308, DRV8301, DRV8304, DRV8305

Hello all,

We are in search for a new motor driver replacing L6235 from ST for a brushless application.  

The driver should have internal FETs. And also take care of the hall signals (also be a controller). The external uC controlling the application should only care about direction and duty cycle. Same as L6235 provides. The ST driver to be replaced has too high RDSon. Thats the motivation for replacement. Except for this the driver is well suited. 

The interface can be any time. Parallel, I2C, SPI. This is not relevant. What is of high relevance is that the FETs are internal and that the driver is also a controller (takes care of the hall signal inputs)

It should accept a bridge voltage of at least up to 36V or if no option exist 24V can be a lesser alternative.

Can you guys recommend any BLDC driver for this application? Does TI have any at all that come close to this?

Extra info: The motor it should drive is the low inductance EC-i 30 from maxon motor.

Best, Christian

  • 0
    TI__Guru** 114905 points

    Hi Christian,

    There is one device with internal FETs and no ability to directly control the halls, and a second device that can control the halls but no internal FETs.

    The DRV8312 with internal FETs can meet the current and voltage requirements. External logic is required to convert the hall signals into PWM inputs.

    The DRV8320H has a 1x PWM mode to directly use the halls, although external FETs are required. The benefit of external FETs is you can decide what RDSon to use.

  • 0 in reply to Rick Duncan
    Prodigy 130 points

    Hi Rick,

    Thanks for your reply. So the short answer is that you do not have a product that has internal FETs and accepts hall inputs? Is that the case?

    I see that you have a number of other predriver 8301,..02,..03,..04,..05 and so on. But to be honest it is very unclear to me what the differences are. Is that clear to you? 

    We can live with external FETs, but need the hall signals to go to the driver. I see around 12 possible candidates for this but I dont see a clear difference between them. Can you outline those differences to me?

    Best, Christian

  • 0 in reply to Christian Ahler
    TI__Guru** 114905 points
    Hi Christian,

    Yes, the short answer is we do not have a product that has internal FETs and accepts hall inputs.

    Based on the need to have the hall signals go to the driver and 36V, please look at the following:

    The DRV832x family of devices, with an absolute maximum voltage of 65V. There are 4 in the family to allow you to choose the options desired.

    The 0 or 3 has either 0 or 3 current sense amplifiers, respectively.
    The "H" is the hardware version which provides basic functionality and a limited programming through pins.
    The "S" is the SPI version allow full programming.
    The "R" version has built in regulator.

    If you can control the voltage spikes on VM, the DRV8307 and DRV8308 with an absolute maximum voltage of 45V would be another option. The DRV8307 can be used to run a sensored BLDC motor, while the DRV8308 has advanced features available. The DRV8308 can run the motor in sinusoidal mode if desired.
  • 0 in reply to Rick Duncan
    Prodigy 130 points
    Rick,

    I see. But to take an example of our still missing overview; DRV8304 does also allow for direct hall inputs. It is not shown in the diagram drawing but explained further into the datasheet. So 04 would also be an option. But you do not include that in your suggestions. So for sure more than 07 and 08 "tolerate" hall signals. To me it is still not clear what the differences are between them. I see they have different number of current amplifiers, yes, but there is still no clear differentiation between DRV8301, 02, 03 and so on. Which of your controllers do except hall signals and can tolerate 36V? And are there any differences we should be aware of such as maturity level or other? Thanks!
  • 0 in reply to Christian Ahler
    TI__Guru** 114905 points
    Hi Christian,

    You are correct; I missed the DRV8304 and the DRV8305. The DRV8304 is in Preview state.

    The DRV832x, DRV8304, and DRV8307/8 have what is referred to as 1x PWM mode. The DRV8304 refers to this mode as Single PWM mode. This mode allows the hall signals to directly control the gate outputs.

    The biggest difference between the devices is the voltage range and the gate drive current. The maximum voltage is 40V for the DRV8304, 42V for the DRV8307/8, 45V for the DRV8305, and 65V for the DRV832x. Gate drive is up to 300mA for the DRV8304, 30mA for the DRV8307, up to 130mA for the DRV8308, up to 1.25A for the DRV8305, and up to 2A for the DRV832x.

    All devices have standard protection features such as undervoltage detection, VDS fault detection, and overtemperature shutdown. The DRV8304, DRV8305, and DRV832x also have gate fault detection.

    The maturity of the devices can be determine by the issue date of the first datasheet. The DRV8307/8 are the oldest released devices (April and February 2014, respectively) ; the DRV8305 next (August 2015), the DRV832x is the newest released device (February 2017), and the DRV8304 is in preview (not released)
  • 0 in reply to Rick Duncan
    TI__Expert 8985 points
    Hi Christian,

    Did Rick's suggestions resolve your question?

    If so, please close this post by accepting the post is resolved in Rick's highlighted in yellow answer above me.

    Thanks!