DRV8332: Is there a way to detect the current of the BLDC motor through the shunt resistors on the negative switch side of the 3-phase?

Sang-il Nam

Expert 2335 points

Part Number: DRV8332
Other Parts Discussed in Thread: BOOSTXL-DRV8323RS

Hi,

I have a motor control board using TI's DRV8332.

This hardware has a shunt resistors on the 3-phase negative switch.

Now I want to control the current of the BLDC motor with this hardware.

Is there a way to detect the current of the BLDC motor through the shunt resistors on the negative switch side of the 3-phase,

instead of the single-shunt resistor on the positive DC-link or negative DC-link?

Thanks In Advance.

over 6 years ago

0 Rick Duncan over 6 years ago

TI__Guru** 114905 points

Hi Nam, Sang-il,

Please refer to Figure 16 of the DRV8332 datasheet. You can configure R50 through R53 as shown to measure the individual phase currents (R50, R52, R53) and the total current (R51). If you do not need the total current, you can short R51.

0 Sang-il Nam over 6 years ago in reply to Rick Duncan

Expert 2335 points

Thank you for answer. I have additional questions.
Is there a other software solution to detect the current of a BLDC motor with only the shunt resistors on the negative switch side of the three-phase, instead of modifying the hardware like you mentioned?

Thanks In Advance.

0 Rick Duncan over 6 years ago in reply to Sang-il Nam

TI__Guru** 114905 points

Hi Nam, Sang-il,

I do not understand your question. What control algorithm do you plan to use?

0 Sang-il Nam over 6 years ago in reply to Rick Duncan

Expert 2335 points

Thank you for your quick reply.

I wonder if I can detect the current flowing through the BLDC motor with only three shunt resistors located on the negative switch side of each phase without the single shunt resistor located on the negative DC-Link side.

I wonder if there is an algorithm that makes it possible.

Thanks in advance.

Nam Sang-il

0 Rick Duncan over 6 years ago in reply to Sang-il Nam

TI__Guru** 114905 points

Hi Nam Sang-il,

Yes, both trapezoidal and sinusoidal algorithms can be used with three shunt resistors located on the negative switch of each phase without the single shunt on the negative DC-Link.

The BOOSTXL-DRV8323RS is an example of this circuit.

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DRV8332: Is there a way to detect the current of the BLDC motor through the shunt resistors on the negative switch side of the 3-phase?