Issue with Stepper Motor Driver over temperature above 60C.

I, Mala Reddy, work at Destaco. Destaco is the company that manufactures the Electrical grippers. These electrical gripper works on 24VDC with PLC communication from the central control unit. We used the Stepper motor to grip the object, which is controlled through the TMC5160 Trinamic chip. While endurance test, we have faced the following issue.

Description of the situation:

• We have an actuator which cycles between two hard stops, and we use StallGuard to detect the location of the hard stops
  • We are using a TMC5160 at 24V and no encoder
  • This has been observed with multiple setups including NEMA14 and NEMA17 motors from multiple manufacturers
  • IRUN is fixed at 31 and Global Scaler is usually between 30 and 40 when it encounters the hard stops
  • VMAX tends to be on the order of 750,000, but this varies.
• When the actuator is run in a heated environment, we start to see inconsistencies / noise in the detected stall location
• We found that the noise is present when the board is heated above about 60C, but not when the actuator is heated.

Please let us know, what could be the cause for above issue.

Please let me know if you need further details to address the issue.

Thanks,

Mala Reddy