STSPIN948 and stepper motor

[giuseppe]

Hi,

does anyone in the world have used a STSPIN948 with a stepper motor?

I'm having many problems, also because of lack of documentation and examples.

I need to control a NEMA 23 motor, but if it turns slowly it works, over 2 turn per second it hangs.

I would know how to set the chip and also how to drive it for better performance.

Thank in advance

[ADAVE.1]

Hi @giuseppe 

If you want to drive the device with a standard stepper algorithm, 2 currents shifted by 90 degrees, I suggest to set the device in mixed decay configuration (MODE1=MODE2=high, MODE3=low), set PWM1A and PWM2A high to turn on the bridges and drive PHA and PHB high or low to force the current direction. You would need two additional signals connected to REFA and REFB (you can use two low pass filtered PWM signals) that determine the current limiter threshold, hence the peak current.

Connect to TOFFA and TOFFB a proper value of resistor and capacitor in accordance to the rate of change of REFA/B and the current ripple you may consider acceptable.

Alessio