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[ausera uirwaij]

Thank you.

[Cristiana SCARAMEL]

Hello @ausera uirwaij​,

which driving topology are you using: full-bridge or single half-bridge?

Could you share your schematic?

The DC motor current have a strange shape, please share an oscilloscope waveforms showing the current and voltage phase.

[ausera uirwaij]

Hello

[Cristiana SCARAMEL]

Hi @ausera uirwaij so you are using a three-phase motor​, good to know.

In the 6Step_Lib.c:

• Voltage Mode: speed loop output is the duty cycle (on-time) of the phase. So an increase of the speed corresponds to an increase of the duty cycle of the PWM output. With this driving mode the output current peak may change along the step.
• Current Mode: speed loop output is the duty cycle of the current reference of the current limiter. With this driving mode the output current peak is maintained at a constant level, controlled by the current reference. The duty cycle of the output phase is not constant since the phase is turned off as soon as the load current threshold is reached.

With current mode, the current is limited thanks to an external comparator (whose inputs are the reference and the voltage across the sense resistor) that triggers the start of the decay time. So a firmware current loop is not needed since the speed loop is the one that controls the current by means of the current reference connected to the comparator.

For further support in the original question please share the above requested oscilloscope waveforms showing the current and voltage phase.

[Cristiana SCARAMEL]

Hi @ausera uirwaij​ there are any updates about your support?

[ausera uirwaij]

Hello @Cristiana SCARAMEL​ ,

Good day,

I'm so sorry I didn't pay attention to my notifications.

​ ​My phase current is bigger compared to commercial drive board with same speed and motor. Capture 3 & Capture 4 show that my board has higher I_pp.

[Cristiana SCARAMEL]

Hi @ausera uirwaij​,

I don’t have enough information to answer your questions.

What is the difference between "your board" and the "commercial drive board"?

Which drivers are you using?

How are you generating PWM signals?

It seems that the PWM signal is affected by noise generated by the switching of the other phases.

[ausera uirwaij]

Hello @Cristiana SCARAMEL​ 

[ausera uirwaij]

Thank you very much for your kindly reply.

[Cristiana SCARAMEL]

Hi @ausera uirwaij​,

I noted that the Hall effect sensors have a different high voltage level in the two boards (5 V in your and 3.3 in the other).

The trigger point of the Hall sensor could change with the supply voltage causing a load angle error.