cancel
Showing results for 
Search instead for 
Did you mean: 

EVSPIN32G4 Over Current Protection (OCP)

1123
Associate II

Hi all , 

I'm currently using the EVSPIN32G4 evaluation board along with MC Workbench for motor control development, and I'm encountering an issue with Overcurrent Protection (OCP) behavior that I can’t quite resolve.

My Setup:
Gain Type: External Gain Net
OCP Threshold (set in MC Workbench): 200A
Shunt Resistor: Physically modified to 1mΩ (0.001Ω)
External Amplifier Gain: 7.33

1746582341903.jpg

1746582329251.jpg

During runtime, I monitored the motor phase current using a current probe and oscilloscope. OCP is triggered at only around 46A, which is far below the configured 200A.

In the firmware, I noticed:

DAC_OCP_Threshold = 7427;

According to the MC SDK, the current conversion factor is calculated using this formula:

#define CURRENT_CONV_FACTOR ((uint16_t)((65536.0 * RSHUNT * GAIN) / ADC_REFERENCE_VOLTAGE))

I get: CURRENT_CONV_FACTOR ≈ 146 ///   I = 7427/146 = 50.9A

In the official ST document UM2850 - Getting Started with EVSPIN32G4, Section 5.5.2 provides a OCP threshold formula.

1746583672261.jpg

  

The formula is used to calculate the actual overcurrent protection (OCP) trigger current based on the hardware resistor network.

I’m unsure whether this discrepancy is due to a misunderstanding on my side, or if there’s a misconfiguration in the setup.I hope someone can help me clarify this issue.

Thanks

0 REPLIES 0