Datasheet

TMC220X, TMC222X DATASHEET (Rev. 1.02 / 2017-MAY-16) 38
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AT#1
Stand still
AT#2
Homing
Ready
Power Up
stealthChop2 regulates to nominal
current and stores result to
PWM_OFS_AUTO
(Requires stand still for >130ms)
N
PWM_GRAD_AUTO becomes
initialized by OTP
Driver Enabled? N
Standstill re-
duction enabled?
Y
Issue (at least) a single step
pulse and stop again, to
power motor to run current
Y
Driver Enabled? N
Y
Move the motor, e.g. for homing.
Include a constant, medium velocity
ramp segment.
Store PWM_GRAD_AUTO or
write to OTP for faster
tuning procedure
Option with UART
PWM_
GRAD_AUTO stored
in OTP?
N
Y
stealthChop2 regulates to nominal
current and optimizes PWM_GRAD_AUTO
(requires 8 fullsteps per change of 1,
typically a few 100 fullsteps in sum)
stealthChop2 settings are optimized!
stealthChop2 keeps tuning during
subsequent motion and stand still periods
adapting to motor heating, supply
variations, etc.
Figure 6.2 stealthChop2 automatic tuning procedure
Attention:
Modifying VREF or the supply voltage VS invalidates the result of the automatic tuning process. Motor
current regulation cannot compensate significant changes until next AT#1 phase. Automatic tuning
adapts to changed conditions whenever AT#1 and AT#2 conditions are fulfilled in the later operation.