Hello there,

I want to use the MP6543 into my toy I’m building. But there is some misunderstanding from my side.

I see there is 2A current continuously the MP6543 can deliver. But I can’t find is it current PER ONE OUTPUT or PER VDD?

I need to understand: what can be CONTINUOUS CURRENT through VDD because I plan to use saddle-shaped waveform to drive my BLDC by MP6543 part and this case the VDD current will be 1.4 times much than current per one OUTPUT PIN.

Please help to understand what is the 2A current in the datasheet: is it VDD or OUT PIN current? And what can be VDD continuous current?

Thx!

Hello goblingol,

I’m not sure I clearly understand the distinction you make. Anyway, you can consider those 2A as the RMS current absorbed by the motor. I assume that is what you mean by VDD current?

Best Regards,

Carmine

Hi Carmine,

thanks for feedback.

Yes, RMS current through motor should be the same as through Vin (that is VDD in my PCB).

So, as I understand from your clarification, the 2A current in the datasheet it is NOT current per one output (SA for example), but the current per motor (that is equal to current per VIN). Correct?

Because Vin pin should be able to flow the 1.4 times more current that one phase (SA for example).

thanks

Hello goblingol,

Yes, even though your example is specific to the waveform you are using. Imagine to have a constant current on a single output: in that case the VDD and phase current are the same.

The definition in my previous reply is a bit more general.

Best regards,

Carmine

Hi,

Actually, the case is little different. Because in case of DC current the current per one output (SA) will be the same as per Vin. I agree with that point. But not in Saddle-shape case: here the RMS current per Vin will be 1.4x times more than RMS current per SA. In general, is because the couple outputs are function at the same time (at different PWMs). There is why the current per Vin is 1.4x times bigger. That is why I’m asking what the current (2A) is in the datasheet: Vin current or output (SA) current.