AMIS30512 ON Semiconductor, AMIS30512 Datasheet - Page 16

• Manufacturer Part Number: AMIS30512
• Description: Micro-stepping Motor Driver
• Manufacturer: ON Semiconductor

NOTE:
Programmable Peak−Current
(coil peak current = Imax) is adjusted by means of an SPI
parameter “CUR[4:0]” (Table 13: SPI Control Register 0).
Whenever this parameter is changed, the coil−currents will
NOTE:
Left: Change from lower to higher resolution. The left−hand side depicts the ending half−step position during which a new step mode
resolution was programmed. The right−hand side diagram shows the effect of subsequent NXT commands on the micro−step position.
Right: Change from higher to lower resolution. The left−hand side depicts the ending micro−step position during which a new step mode
resolution was programmed. The right−hand side diagram shows the effect of subsequent NXT commands on the half−step position.
Table 10. Programmable Peak Current CUR[4:0]
Current Range
The amplitude of the current waveform in the motor coils
It is advised to reduce the micro−stepping resolution only at micro−step positions that overlap with desired micro−step positions of
the new resolution.
0
1
Changing the current over different current ranges might lead to false over current triggering.
Halfstep
Change from lower to higher resolution
Iy
endpos
CUR[4:0] Index
DIR
10
12
13
14
15
11
0
1
2
3
4
5
6
7
8
9
Ix
NXT4
NXT3
1/4
NXT2
Figure 11. NXT−Step Mode Synchronization
th
step
Current (mA)
Iy
NXT1
100
122
135
149
164
110
15
30
45
50
55
61
67
74
82
91
startpos
http://onsemi.com
DIR
Ix
16
Current Range
be updated immediately at the next PWM period. The
impedance of the bottom drivers is adapted with the current
range: See Table 4: DC Parameters.
2
3
Change from higher to lower resolution
1/8
th
Iy
endpos
step
CUR[4:0] Index
DIR
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
Ix
NXT3
NXT2
NXT1
Halfstep
Current (mA)
Iy
startpos
181
200
221
244
269
297
328
362
400
441
487
538
594
656
724
800
DIR
Ix