Datasheet

TMC2590 DATASHEET (V1.0 / 2019-FEB-22) 34
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In Figure 8.3, the first STEP cycle is long enough to set the STST bit. This bit is cleared on the next
STEP active edge. Then, the STEP frequency increases and after one cycle at the higher rate MicroPlyer
increases the interpolated microstep rate. During the last cycle at the slower rate, MicroPlyer did not
generate all 16 microsteps, so there is a tiny jump in motor angle between the first and second cycles
at the higher rate.
8.5 Standstill Current Reduction
When a standstill event is detected, the motor current should be reduced to save energy and to
reduce heat dissipation in the power MOSFET stage. Especially halfstep positions are worst-case for
motor and driver with regard to the distribution of the power dissipation, because the full energy is
consumed in one bridge and one motor coil.
Hint
Implement a current reduction to 10% to 75% of the required run current for motor standstill. This
saves more than 50% to more than 90% of energy. The actual level depends on the required holding
force and on the required microstep precision during standstill. In standalone mode, a reduction to
50% current is possible using a configuration input.