some Question about the function "adc" when i use s12zvml128 control pmsm foc (MC9S12ZVML128_PMSM_)

[Clarkhe]

Hi

I use the single resistance sampling mode without a reference voltage of 2.5V. At present, I can only sample the current in one direction. Can I use the current demo simply to modify it? What is the efficiency?

Is there any problem. In addition, when the single resistance bus sampling will appear negative current?

[pachamatej · Accepted solution]

Hi,

I'm just assuming, so if I'm not correct, please clarify.

In case you are using our devkits

https://www.nxp.com/design/development-boards/automotive-motor-control-solutions/magniv-and-s12-solu...

https://www.nxp.com/design/development-boards/automotive-motor-control-solutions/magniv-and-s12-solu...

https://www.nxp.com/design/development-boards/automotive-motor-control-solutions/magniv-and-s12-solu...

All three boards are capable of using DC-link shunt resistor to control a 3-ph motor, but the last two can do only this technique (aka "single-shunt" only).

If you are using the MTRCKTSPNZVM128 or MTRCKTSBNZVM128 (physically, it is the same devkit), then I would recommend to verify the jumper settings first according to the Quick start guide and the dedicated application note - there is a different configuration for dual-shunt and for single-shunt.

By the way, in all the cases, the reference voltage is 2.5V and thanks to that, the ADC can see positive and negative currents.

If you see any difference from what you want to achieve and from the description above, please let us know.

Best regards.

Matej

[Clarkhe]

OK,thankyou 

[danielmartynek]

Hi,

I'm not sure if I understand.

Can you please elaborate?

Thank you,

BR, Daniel