AMIS-30621 Datasheet, PDF (17/59 Pages) AMI SEMICONDUCTOR – LIN Microstepping Motordriver

AMIS−30621
Position Periodicity
Depending on the stepping mode the position can range
from –4096 to +4095 in half−step to –32768 to +32767 in
1/16^th micro−stepping mode. One can project all these
positions lying on a circle. When executing the command
SetPosition, the position controller will set the
movement direction in such a way that the traveled distance
is minimal.
The figure below illustrates that the moving direction
going from ActPos = +30000 to TagPos = –30000 is
clockwise.
If a counter clockwise motion is required in this example,
several consecutive SetPosition commands can be
used.
+10000
+20000
ActPos = +30000
0
Motion direction
TagPos = −30000
−10000
−20000
Figure 9. Motion Direction is Function of Difference
between ActPos and TagPos
Hardwired Address HW2
In the drawing below, a simplified schematic diagram is
shown of the HW2 comparator circuit.
The HW2 pin is sensed via 2 switches. The DriveHS and
DriveLS control lines are alternatively closing the top and
bottom switch connecting HW2 pin with a current to resistor
converter. Closing S_TOP (DriveHS = 1) will sense a current
to GND. In that case the top I³ R converter output is low,
via the closed passing switch S_{PASS_T} this signal is fed to the
“R” comparator which output HW2_Cmp is high. Closing
bottom switch S_BOT (DriveLS = 1) will sense a current to
VBAT. The corresponding I³ R converter output is low and
via S_{PASS_B} fed to the comparator. The output HW2_Cmp
will be high.
I→R
S_{PASS_T}
1 kW
S_TOP
HW2
S_BOT
1
2
3
1 = R2GND
2 = R2VBAT
3 = OPEN
DriveHS
DriveLS
LOGIC
‘‘R”−Comp
I/R
S_{PASS_B}
Debouncer
COMP 32 ms
R_th
HW2_Cmp
Figure 10. Simplified Schematic Diagram of the HW2 Comparator
3 cases can be distinguished (see also Figure 10 above):
• HW2 is connected to ground: R2GND or drawing 1
• HW2 is connected to VBAT: R2VBAT or drawing 2
• HW2 is floating: OPEN or drawing 3
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17
State
High
Low
Float