Datasheet

TMC2209 DATASHEET (Rev. 1.03 / 2019-JUN-26) 25
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5.2 Velocity Dependent Control
VELOCITY DEPENDENT DRIVER FEATURE CONTROL REGISTER SET (0X10…0X1F)
R/W
Addr
n
Register
Description / bit names
W
0x10
5
+
5
+
4
IHOLD_IRUN
Bit
IHOLD_IRUN – Driver current control
4..0
IHOLD (Reset default: OTP)
Standstill current (0=1/32 … 31=32/32)
In combination with StealthChop mode, setting
IHOLD=0 allows to choose freewheeling or coil
short circuit (passive braking) for motor stand still.
12..8
IRUN (Reset default=31)
Motor run current (0=1/32 … 31=32/32)
Hint: Choose sense resistors in a way, that normal
IRUN is 16 to 31 for best microstep performance.
19..16
IHOLDDELAY (Reset default: OTP)
Controls the number of clock cycles for motor
power down after standstill is detected (stst=1) and
TPOWERDOWN has expired. The smooth transition
avoids a motor jerk upon power down.
0: instant power down
1..15: Delay per current reduction step in multiple
of 2^18 clocks
W
0x11
8
TPOWER
DOWN
TPOWERDOWN (Reset default=20)
Sets the delay time from stand still (stst) detection to motor
current power down. Time range is about 0 to 5.6 seconds.
0…((2^8)-1) * 2^18 t
CLK
Attention: A minimum setting of 2 is required to allow
automatic tuning of StealthChop PWM_OFFS_AUTO.
R
0x12
20
TSTEP
Actual measured time between two 1/256 microsteps derived
from the step input frequency in units of 1/fCLK. Measured
value is (2^20)-1 in case of overflow or stand still.
The TSTEP related threshold uses a hysteresis of 1/16 of the
compare value to compensate for jitter in the clock or the step
frequency: (Txxx*15/16)-1 is the lower compare value for each
TSTEP based comparison.
This means, that the lower switching velocity equals the
calculated setting, but the upper switching velocity is higher as
defined by the hysteresis setting.
W
0x13
20
TPWMTHRS
Sets the upper velocity for StealthChop voltage PWM mode.
TSTEP ≥ TPWMTHRS
- StealthChop PWM mode is enabled, if configured
When the velocity exceeds the limit set by TPWMTHRS, the
driver switches to SpreadCycle.
0: Disabled
W
0x22
24
VACTUAL
VACTUAL allows moving the motor by UART control.
It gives the motor velocity in +-(2^23)-1 [µsteps / t]
0: Normal operation. Driver reacts to STEP input.
/=0: Motor moves with the velocity given by VACTUAL. Step
pulses can be monitored via INDEX output. The motor
direction is controlled by the sign of VACTUAL.