DRV8316: MCF8316 min speed

Hi Asaf,

Thanks for your question, please give me a day or two to get back.

Regards,
Sachin S

Hello Asaf,

For 0.2RPM, MCF8316 may not be ideal, since the BEMF is very low at low speeds. Would you willing to evaluate our MCTx portfolio?

Thanks and regards,
Sachin S

Hi Sachin, thank you for your answer.

We've decided on a sinusoidal drive (and motor) for the following reasons:
1. We are aiming at minimizing torque ripple since we need the rotation to be exceptionally smooth.

2. We're using a high resolution rotary encoder for position feedback, and so as we understood it, BEMF may not be so relevant. Please correct me if I'm wrong here.

Using the MCF8316, and a high resolution encoder, should I be able to run my motor at my intended speed?

Hello Asaf,

Understood your requirement. The MCF8316C is a sensor-less driver. You could look at the DRV10970. It is a sensored sine/trap device.

Thanks and regards,

Sachin S 

Hi Sachin!

Thanks for your answer!
Reading through the DRV10970, it seems like it is designed for either differential or single-ended Hall sensor based applications. My application scenario does not include hall sensors, but does include a QEP encoder. 

Is there a similar device working with an encoder, and/or a device implementing an FOC drive?

Additionally, could you tell me a bit about the differences between the DRV10xxx family and the DRV8xxx family?

Hi Asaf,

Sorry I overlooked that you mentioned you use a high resolution encoder. 

Asaf Pipman said:

Reading through the DRV10970, it seems like it is designed for either differential or single-ended Hall sensor based applications. My application scenario does not include hall sensors, but does include a QEP encoder.

Currently we do not have a FOC algorithm integrated product which uses a QEP encoder.

Asaf Pipman said:

Is there a similar device working with an encoder, and/or a device implementing an FOC drive?

The DRV10xxx and MCx portfolio has the control algorithms integrated in to the device. The DRV8xxx family has only the driver part, you will need to implement the driving algorithm yourself.

Asaf Pipman said:

Additionally, could you tell me a bit about the differences between the DRV10xxx family and the DRV8xxx family?

Could you share your motor datasheet so that I can look into it and offer suggestions?

Regards,

Sachin S

Hi Sachin!
Sure, here is the data sheet I had received from our motor supplier. Its not very detailed so I hope this is enough

Regarding a solution where I implement the driving algorithm, like the DRV8xxx, I was hoping I could use TI's MotorControlSDK to generate a driving algorithm for me, with some higher level PID logic on my part to get to my target position.
Reading through the Motor Control SDK Universal Project and Lab user guide , I think I'm not mistaken in thinking this is possible.
Specifically, I also chose a the Sitara AM263 to run this code on, so theoretically, this should be as easy as it can be.
We are having issues using the LP-AM263 with the DRV8613EVM though, and I'm beginning to worry I've made some mistake along the way.
Could you comment on this setup please? Should the DRV8316 be able to drive a BLDC sinusoidal motor using FOC drive generated by the MotorControlSDK on a Sitara AM623?

Hi Asaf,

Let me check with team on this. Give me a day to get back.

Thanks and regards,
Sachin S

Hi Suresh,

The MotorControlSDK is designed for the C2000 family, any reason why you chose Sitara devices?

Thanks and regards,

Sachin S

Hi Suresh!

We needed a general purpose, relatively high performance CPU, which supports multiple protocols and features (SPI, I2C, ADC/DAC, high count of GPIOs, etc) and the Sitara seemed like a good candidate. 

Thanks Asaf for the information,

The C2000 devices too have these features, and the MotorControlSDK is designed for C2000. Could you check the the C2000 portfolio? This may ease your development since MotorControlSDK is available.

Regards,
Sachin S

I understand your point, and will look into the C2000 portfolio, but since I have quite a few Sitara am263P4 launch pads, I would like to keep developing on it in the meantime.
What would I do if I had chosen an ST microchip as my CPU. Surely I can use the DRV to control motors with an ST microchip. Could I not have used the motorcontrolSDK libraries then? how would that process go?

Hi Asaf,

Your point is valid, I may be mistaken here. Let me check with the team on whether MotorControlSDK also supports Sitara processors.

Could you also let me know the specific issues you are facing with your setup?

Regards,

Sachin S

Hello Asaf,

I am assigning this e2e to a Sitara team member, he will be more knowledge-able to answer this.

Thanks and regards,

Sachin S

Hi Masoud!
Thank you for the answer.

Could you tell me if the DRV8316T (Hardware variant, no SPI) could be used with the LP-AM263?

Also, I'm a bit confused about the description of these products. Apologies, I'm new to thos whole motor buisness.

Tha BOOSTXL-3PHGANINV is described as a three phase inverter while the DRV8316 is a three phase PWM motor driver.
Are these two used for driving BLDCs? I'm sensing there is a difference in their intended use which I'm not fully grasping.

Thanks

Hi Sachin!
I wanted to make sure before I order, that the LAUNCHXL-F28P65X will work for me to drive a BLDC motor using a QEP input using the MotorControlSDK.
I'm targeting this https://www.ti.com/product/TMS320F28P650DK as my IC.

Please let me know.

Thank you Masoud for the reply, I will order a few EVMs then.
Could you elaborate on what you mean by the quote below, I want to make sure I'm following you completely.

Masoud Farhadi said:

You might also want to think about moving over the C2000 universal motor control solution for your specific core.

I mean we have "servo_drive_with_can" example but not limited to this one. there are other examples which can be migrated to this device.

Best Regards,

Masoud