DRV8889-Q1: DRV8889-Q1's electrical cycle

Michael Wang3

Part Number: DRV8889-Q1

the data sheet says "The TRQ_COUNT value is continuously averaged and it gets updated at the end of every half electrical cycle. At the most, it takes two electrical cycles to detect stall."

my question is: what is an "electrical cycle"? is it a full STEP (a period of a full driving sine wave)?

Thanks,

Michael

over 4 years ago

0 Pablo Armet over 4 years ago

TI__Mastermind 37683 points

Hi Michael,

One full electrical cycle refers to a complete 360 electrical degrees rotation. The figure below shows a complete electrical cycle.

0 Michael Wang3 over 4 years ago in reply to Pablo Armet

Prodigy 30 points

Thanks Pablo for your reply!

My understanding is that the waveforms show only one STEP in microstepping mode, not a 360 degree rotation which would consists many steps. still not clear. Let's see what others say. thanks

0 Rick Duncan over 4 years ago in reply to Michael Wang3

TI__Guru** 114905 points

Hi Michael,

The waveform shown is 360 degrees electrical, and consists of 64 microsteps assuming 1/16 microstepping.

Please note Table 3 of the datasheet. 4 full steps are required to rotate 360 electrical degrees.

Each full step changes the electrical angle by 90 degrees.

0 Michael Wang3 over 4 years ago in reply to Rick Duncan

Prodigy 30 points

Hi Rick,

Thanks for the detailed explain! Very clear. Got your point. I should say thanks again to Pablo. question solved!

Michael W

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DRV8889-Q1: DRV8889-Q1's electrical cycle