AMC3330: Schematic verification

Viknesh Vadivel

Intellectual 310 points

Part Number: AMC3330

Tool/software:

Hi Team,

Good day!....,

Y- BLDC motor is connected to the output connector.

I need to measure the voltage in each individual phase of motor. But due to no return neutral path I am trying to measure the VL-L voltage.

For Y connection, VLL = √3 VPh

Finally I will divide VLL/√3 time get the phase voltage

Since there will not be any return path from motor to inverter bridge. Do I need to connect HGND to chassis/some how to earth?

Thanks,

Regards,

Ram.

8 days ago

0 Eva Mason 3 days ago

TI__Expert 5705 points

Hi Ram,

Thank you for your question. For grounding, where would you connect HGND to earth ground? In the schematic you write that VDC- is connected to GND, and it seems VDC- is on the high-side of the device while GND is on the low-side. On these isolated devices, the high side and low side grounds must not be connected as that could compromise the isolation barrier. I think your schematic overall looks good overwise.

Best regards,

Eva

0 Viknesh Vadivel 13 hours ago in reply to Eva Mason

Intellectual 310 points

Hi Eva,

Thanks for your schematic review inputs. I will modify the ground isolation accordingly.

Basically I need to measure BLDC Motor Phase Voltage and referred few of your app notes.

Please let me know whether the below circuit will measure Phase voltage[Both Positive & Negative voltage] or this circuit is intended to measure only the peak positive voltage for certain period of time.

https://www.ti.com/lit/an/slyt827/slyt827.pdf?ts=1733844670085&ref_url=https%253A%252F%252Fwww.ti.com%252Fsitesearch%252Fen-us%252Fdocs%252Funiversalsearch.tsp%253FlangPref%253Den-US%2526nr%253D62574%2526searchTerm%253Dac+voltage+sensor

Thanks,

Regards,

Ram.

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AMC3330: Schematic verification