The next step is to set the registers in the L6470 to compensate for the back EMF, so that the current is approximately constant over the speed range. These values, calculated following mathematical rules explained in the AN4144, will return the correct slope to compensate the BEMF. Again, the scope is triggered at the start of a movement and it can be seen that the Back EMF compensation has increased, the applied voltage as speed increased, and the peak current remains approximately constant over the speed range. It is also possible to over compensate and have the current increase with speed by setting the slope higher, not a desirable condition.