AMIS-30622_13 Datasheet, PDF (18/50 Pages) ON Semiconductor – I2C Micro-Stepping Motor Driver

AMIS−30622
+10000
0
+20000
ActPos = +30000
Motion direction
TagPos = −30000
−10000
−20000
Figure 9. Motion Direction is Function of
Difference between ActPos and TagPos
Hardwired Address HW
In the drawing below, a simplified schematic diagram is
shown of the HW comparator circuit.
The HW pin is sensed via 2 switches. The DriveHS and
DriveLS control lines are alternatively closing the top and
bottom switch connecting HW 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 HW_Cmp is high. Closing
bottom switch S_BOT (DriveLS = 1) will sense a current to
V_BAT. The corresponding I ³ R converter output is low and
via S_{PASS_B} fed to the comparator. The output HW_Cmp
will be high.
S_{PASS_T}
I/R
S_TOP
1k
HW
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
HW_Cmp
Figure 10. Simplified Schematic Diagram of the HW Comparator
3 cases can be distinguished (see also Figure 10 above):
• HW is connected to ground: R2GND or drawing 1
• HW is connected to VBAT: R2VBAT or drawing 2
• HW is floating: OPEN or drawing 3
State
High
Low
Float
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