In datasheets from Allegro and Sanken the typical application are without diodes across stepper coils.
Same implementation on printer drivers.
So , a few questions:
1) is correct to think they use avalanche breakdown of rugged MOSFETs for BEMF decay ?
2) What will happen with torque if I'm putting diodes across coils ?(guess I'll get slow instead fast decay)
3) Can I use avalanche rated MOSFETs in a discrete driver without diodes across coils?
4) I never seen a fried SLA 7026(7024,7029), IS a discrete driver a reliable circuit (without diodes ) ?