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DRV10974: DRV10974

Part Number: DRV10974
Other Parts Discussed in Thread: DRV8306, DRV8320, DRV8304
Hi
I need five amps continous.
 Please look at attached cicuit.
If i omitted the bipolar transitors , can i not add N and  P channel mosfet , with a fast recovery diode
feed back to the  DRV10974 , as feed back or omit the diode totally.(circuit not totally correct , something i found and planned to modify).
Think as two BJT inside ic , i add two mosfets to switch coil , communtation feed back through diode or no diode.
Your thoughts please ?
Thanks
Colin 
  • Hello Colin,

    I saw your other post with the DRV10974 about geting more current, and it seems that there is a fundamental misunderstanding what the DRV10974 is, and what it does.

    To drive a motor, there are 3 blocks that are needed:

    • Control
    • Gate Driver
    • FETs

    The FETs connect directly to the motor phase, as switching them on will deliver current through the motor. The gate driver is used to turn on the FETs as PMOS is not usually used to drive the motor because of the power dissipation and cost for the same size, this means the voltage applied to the gates of the high side NMOST FET needs to be higher than the voltage applied to the motor (to fulfill VGS >Vth). The Control is algorithm that determines when the turn the FETs on and off in an attempt to get motion out of the motor.

    So, your diagram has the FETs on the right hand side, the Gate drive circuit in the middle, and a floating arrow pointing to a MCU for Control. You have all of the blocks to drive a motor and a DRV10974 isn't even needed in your case.

    The value TI brings is that the DRV10974 integrates Control, Gate Driver, and FETs into one package so no other components are needed. There is no feedback that the DRV10974 can provide to help drive the gates of FETs. This circuit does not relate to the DRV10974 in anyways because it does not support the DRV10974, it replaces it.

    DRV10x does Control + Gate Driver + FETs, DRV83x (usually) is just Gate Driver, and TI offers some power FETs of various specs: https://www.ti.com/power-management/mosfets/overview.html  

    Best,

    -Cole

  • Thank you,

    I am looking for a easy solder package eg soic 20 pin that has internal fet driver as well as the control algorithm in one package.I will add 

    external fets to drive 18volt three phase brushless motor.My microcontroller will provide speed control via

    PWM,spi , i2c or DAC.I am using  ATTiny3216

    Any suggestions PLEASE

    Thank you

    Colin

  • Sorry , forget to mention my current that i need for various motors can be as high as eight amps

  • Hey Colin,

    Perfect, thanks for the clarification.

    Unfortunately, our Gate Driver + Integrated Control portfolio is lacking a bit (as of 2020).

    There are plenty of DRV83x devices with a simple trapezoidal algorithm which can be implemented using blind commutation, or hall sensor feedback. Check the datasheets for more information:

    • DRV8306: made specifically for sensored trap and my recommended part for you
    • DRV8304 and DRV8320: could be blind commutation or sensored trap. Its a more flexible part made for MCU's that contain the control

    If you want more complex control, such as, sinusoidal, FOC, 150 degree, or other commutation types, TI currently doesn't offer much in this power bracket but it is on the roadmap for future development.

    Best,

    -Cole