Application Note AN062 (V1.00 / 2021-MAR-12) 5
www.trinamic.com
near the motor temperature limit, or near the limit of the power supply, countercheck motor heat-
up in your application. Adapt motor current slightly if required.
Item Change in TMC26xC Possible impact on application
chopper with
TMC262C
Internal noise sources have been reduced.
Noise caused by internal wiring voltage drop
makes up for up to 10mV within the TMC26x.
This reflects in a slightly lower sense input
More silent motor, especially
with low velocity. TMC26xC
effective motor is current about
1%-3% higher.
threshold setting
SGT
The internal calculation has been corrected to
avoid loss of StallGuard™ signal in
combination with negative SGT settings.
StallGuard™ at a very sensitive
range, compare the results
carefully.
In case the application uses SGT
settings below -5, check the
StallGuard™ sensitivity, and
tune SGT in case of too low
CoolStep™
behavior
A consequence of better internal current
sensing the resulting motor phase current can
be 1%-3% higher than before. This results in
ca. 1%-3% more torque.
Previous StallGuard™ limits may
not fit exactly due to the
current/torque changes.
Follow the StallGuard™ and
CoolStep™ Parameterization
Appnote / a link is provided at
the end of this document.
When running on internal clock frequency
(which has a manufacturing stray as before)
the frequency for the SPI bus should be
chosen in a safe range. The TMC26xC has
a slightly lower center value of the
production stray of the internal oscillator.
However, this center value is still within the
min/max values of the non-C-devices.
Basically, no change is required
if the SPI bus clock frequency
has been chosen in a safe rage
before already.
TMC26xC shows ca. 1%-3% higher current (=
1%-3% more torque), better internal sensing,
different center value of production stray of
the internal oscillator, and improved
precision and speed of internal Break-before
make detector.
Motor resonances shift to a
slightly different frequency and
might have different effect in
combination with the
application mechanics.
The SpreadCycle™ chopper
parameters may need to be
adapted.
Follow the SpreadCycle™
Parameterization Appnote / a
link is provided at the end of
The TMC26xC uses some of the GND pins of
the original device as individual return for the
sense resistor. In case, the PCB layout fails to
contact all GND pins of the TMC26x to the
GND plane using short traces, the current
Parameterization Appnote / a
link is provided at the end of
this document.