DRV8220EVM: questions about DRV8220EVM

Jimmy Lai

Expert 6845 points

Part Number: DRV8220EVM
Other Parts Discussed in Thread: DRV8220,

Dear Team:

If the customer increases the operating frequency, the current will become a triangle wave as shown in the figure below

Is this normal? What is the reason?

step frequency is 500K. If 1/256 microsteps are used, the highest control can only reach 1.95pps

Can we increase it to 1M or 1.5M? Do we have another solution can reach higher step frequency ?

Many Thanks,

Jimmy

over 3 years ago

0 Ryan Kehr over 3 years ago

TI__Guru 54755 points

Jimmy,

I am confused on the DRV8220EVM. Can you check the part number again? DRV8220 does not have a step/dir interface.

The reason the current is triangular is due to the back-emf generated by the motor that is opposing the applied current. The device is not able to regulate to a sinusoidal current as a result of the BEMF.

Regards,

Ryan

0 Jimmy Lai over 3 years ago in reply to Ryan Kehr

TI__Expert 6845 points

Hi Ryan,

Sorry for my typo.

Is DRV8424EVB, Thanks!

BR,

Jimmy

0 Ryan Kehr over 3 years ago in reply to Jimmy Lai

TI__Guru 54755 points

Jimmy,

No issue. Makes more sense now. Was my explanation of the issue clear to you?

Regards,

Ryan

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DRV8220EVM: questions about DRV8220EVM