User Manual

TMC262-EVAL MANUAL (V. 0.16 / 2010-Aug-13) 11

6.2.6 Optimizing the chopper settings

In principle, you can run the motor with default settings, but you might want to try improving or

modifying the chopper setting for smoothest performance of the motor and for low chopper noise. Start

the motor at the desired velocity, e.g. a medium velocity to tune const toff mode fast decay time, or a

low velocity to tune chopper hysteresis setting or sine wave offset in const toff mode. Go to the tab

CHOPCONF. There is no need to modify the blank time, unless you change the MOSFETs on the

board. Now, you can select standard chopper or classical const toff chopper. For both modes, the off

time TOFF is a major component. A setting between 4 and 7 fits most motors. In the standard mode,

you can check behavior for different HSTART settings to improve motor behavior. In constant toff

mode, a positive sine wave offset improves zero transition performance; fast decay time influences

motor noise. You might try pure slow decay operation if fastest velocity is desired.

6.3 Writing the settings to a .C file

You can load and store all settings made in the evaluation board. They are stored in a .262 text file,

which is user readable.

figure 6: .262 file opened in text editor

In order to transfer the settings into your own software, there is a C language export function. This will

write out the initialization values for the TMC262 in a C syntax form, which allows easy sending via a

microcontroller SPI interface.

figure 7: .c file opened in text editor