Datasheet

TMC4361A Datasheet | Document Revision 1.22 • 2017-JAN-12
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to technical change reserved. Download newest version at: www.trinamic.com .
Read entire documentation; especially the “Supplemental Directives” on page 224.
 MAIN MANUAL 
Current Scaling during Motion
If the current values need to be scaled during motion, several options are available. Up to three
scaling values can be selected: Two drive scaling values and one boost scale value. Different
scale values can be automatically assigned to the various sections of the velocity ramp.
Drive scaling is the preferred direct and mostly unconditional scaling option. If no
boost scaling is enabled, the current values are scaled according to the given scale
value, independent of the present ramp status.
In order to set up and enable only drive current scaling, do as follows:
Action:
 Set DRV1_SCALE_VAL = SCALE _ VALUES (15:8) according to the maximum
current during motion.
 Set drive_current_scale_en = 1 ( CURRENT_CONF register 0x05).
 Set closed_loop_scale_en = 0 ( CURRENT_CONF register 0x05).
Result:
As long as no other motion scale options are activated the current values of the MSLUT
are scaled according to DRV1_SCALE_VAL during motion ( VACTUAL <> 0).
A second drive scale parameter can be assigned in order to differentiate the motion
scaling according to the internal ramp velocity.
In order to set up and enable drive current scaling with two different scaling
values, do as follows:
Action:
 Set VDRV_SCALE_LIMIT register 0x17 [pps] according to switching velocity at
which drive scaling will change.
 Set DRV1_SCALE_VAL = SCALE _ VALUES (15:8) according to maximum current
during motion below VDRV_SCALE_LIMIT .
 Set DRV2_SCALE_VAL = SCALE _ VALUES (23:16) according to maximum current
during motion beyond VDRV_SCALE_LIMIT .
 Set drive_current_scale_en = 1 ( CURRENT_CONF register 0x05).
 Set sec_drive_current_scale_en = 1 ( CURRENT_CONF register 0x05).
 Set closed_loop_scale_en = 0 ( CURRENT_CONF register 0x05).
Result:
As long as no boost scaling is activated, the current values of the MSLUT are scaled
according to DRV1_SCALE_VAL as long as VACTUAL ≤ VDRV_SCALE_LIMIT .
Whenever VACTUAL > VDRV_SCALE_LIMIT the current values are scaled according
to DRV2_SCALE_VAL .
Drive Scaling
Alternative Drive
Scaling