Other Parts Discussed in Thread: DRV8306, DRV8320, DRV8304
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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:
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:
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