Technosoft 2019
16
iMOTIONCUBE Technical Reference
3.2.3
MOTIONCUBE CAT-STO PCB Footprint
For iMOTIONCUBE CAT-STO motherboard PCB design, use the dimensional drawing from
a .dxf file at [email protected].
Figure 3.4
iMOTIONCUBE CAT-STO PCB Footprint
All dimensions are in mm. Holes are marked with
RED
.
3.3
Motherboard PCB Design
It is recommended to use a multi-layer PCB for the motherboard, in order to have enough room for routing all the pins
of the iMOTIONCUBE. Using a 2-layer PCB is possible when some of the iMOTIONCUBE pins remain un-connected.
Below is a list of recommendations for the PCB design of the motherboard:
•
Motor supply and motor outputs: use islands / areas of copper to escape connector area; this will maximize
current capability. When using simple tracks, use at least 100mil cross section (75mil track width for 1oz/ft
2
copper thickness) – for iMOTIONCUBE.
•
Motor supply and ground return tracks between iMOTIONCUBE and the nearby V
MOT
decoupling capacitor are
to be considered as EMI sources, and kept to a minimum length.
•
Place the decoupling capacitors on V
MOT
and V
LOG
(see also 0 Power Supply Connection) as close as
physically possible to the iMOTIONCUBE, to minimize EM radiated emissions. For un-shielded applications
(no metallic box) and typical EMC regulations, the spacing between iMOTIONCUBE and capacitors must be
less than 3 centimeters.
•
In multi-axis applications (multiple iMOTIONCUBE drives on the same motherboard), it is preferable to have a
separate decoupling capacitor for each drive’s V
MOT
. For V
LOG
it is acceptable to share one decoupling
capacitor for two drives.
•
For stringent EMI requirements, it may be necessary to add common-mode filtering on the motor and/or logic
supply inputs. Be sure to use 3-phase EMC filters, not 2-phase filters, in order to fulfill the basic requirement
of zero common-mode current through the filter. This is necessary because the ground negative return is
shared between V
MOT
and V
LOG
.
•
Motor outputs shall be routed with parallel traces, and minimizing the loop area between these tracks. Avoid
placing components above or below the motor output tracks, as these components may become effective
antennas radiating EMI. If possible, route all 4 motor outputs in strip-line configuration (above or below a
ground plane).
•
For stringent EMI requirements, it may be necessary to add common-mode inductors on the motor outputs.
Place these filters near the iMOTIONCUBE, not near the external connector, to reduce radiation from the PCB
tracks.
