DRV8870: How to use DRV8870 to drive a single-phase BLDC

Bella (GZ) Li

Intellectual 885 points

Part Number: DRV8870
Other Parts Discussed in Thread: DRV8801A-Q1, DRV8231A, DRV8251A

hi,

Thank you for your support.

As we known, there are no products in our company to drive single-phase BLDC directly.

So I want to design the single-phase BLDC by DRV8870 ,diagram is shown below:

I have the following questions:

1.How is the current direction of BLDC controlled?

2.How is the speed of BLDC controlled?

3.Does the DRC8870 output require a filter?

4.How the output logic is different for BDC and single-phase BLDC?

Looking forward to hear from you.

over 1 year ago

0 Pablo Armet over 1 year ago

TI__Mastermind 37683 points

Hi Bella,

I am from the brushed and steppers PL so I am not too familiar with BLDC motors. However, I found this app-note with useful information on BLDC motors.

This reference design shows how a brushed DC motor driver can be configured to drive a single phase BLDC with additional circuitry. In this example, the DRV8801A-Q1 is used but a similar procedure can be used for the DRV8870.

I hope all of the questions are answered in the reference design. Please let me know if there are any more questions.

Regards,

Pablo Armet

0 Bella (GZ) Li over 1 year ago in reply to Pablo Armet

TI__Intellectual 885 points

hi Pablo

Thank you for your support and share.

I have almost read the reference design.

But I didn't find a way to control BLDC steering. In which case the rotation will be clockwise and in which case it will be counter-clockwise.
Can you give me the answer?

0 Pablo Armet over 1 year ago in reply to Bella (GZ) Li

TI__Mastermind 37683 points

Hi Bella,

The direction of rotation will depend on the control input and the control truth table (see datasheet).

By the way, I talked with out BLDC team for support. They mentioned the DRV8251A or DRV8231A will be better drivers for this application. These two devices are similar to the DRV8870.

Regards,

Pablo

0 Bella (GZ) Li over 1 year ago in reply to Pablo Armet

TI__Intellectual 885 points

hi Pablo,

I have received,

Thank you Pablo

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DRV8870: How to use DRV8870 to drive a single-phase BLDC