Phase current control for L6470h

[KFan]

Hi dear,

I designed a step motor driver board with L6470h and tested it. There are some problems with the board.

I set the run current, hold current, ACC, ACC current, DEC, DEC current at the fixed value, and then changed the MAX speed, then the actual phase current was changed according to the changed speed as shown in the following list.

But I think the phase current should be a fixed value based on the mentioned fixed values. Please help to find the cause for this problem.

Thanks.

[KFan]