AMIS-30624 Datasheet, PDF (11/56 Pages) AMI SEMICONDUCTOR – I2C Microstepping Motordriver

AMIS-30624
12.2 Maximum Velocity
For each stepping mode, the maximum velocity V_max can be programmed to 16 possible values given in
Table 7.
The accuracy of V_max is derived from the internal oscillator. Under special circumstances it is possible to change the V_max parameter
while a motion is ongoing. All 16 entries for the V_max parameter are divided into four groups. When changing V_max during a motion the
application must take care that the new V_max parameter stays within the same group, otherwise steps might be lost.
Table 7: Maximum Velocity Selection Table
Vmax Index
Vmax
Hex
Dec
(Full-step/s)
Group
0
0
99
A
1
1
136
2
2
167
3
3
4
4
197
213
B
5
5
228
6
6
243
7
7
273
8
8
303
9
9
334
A
10
364
C
B
11
395
C
12
456
D
13
546
E
14
729
D
F
15
973
Half stepping
(Half-step/s)
197
273
334
395
425
456
486
546
607
668
729
790
912
1091
1457
1945
Stepping Mode
1/4^th
1/8^th
Micro-stepping
Micro-stepping
(Micro-step/s)
(Micro-step/s)
395
790
546
1091
668
1335
790
1579
851
1701
912
1823
973
1945
1091
2182
1213
2426
1335
2670
1457
2914
1579
3159
1823
3647
2182
4364
2914
5829
3891
7782
1/16^th
Micro-stepping
(Micro-step/s)
1579
2182
2670
3159
3403
3647
3891
4364
4852
5341
5829
6317
7294
8728
11658
15564
12.3 Minimum Velocity
Once the maximum velocity is chosen, 16 possible values can be programmed for the minimum velocity V_min.
Table 8 provides the obtainable values in full-step/s. The accuracy of V_min is derived from the internal oscillator.
Table 8: Obtainable Values in Full-step/s for the Minimum Velocity
Vmin Index
Hex Dec
Vmax
Factor
A
99
Vmax (Full-step/s)
B
C
D
136 167 197 213 228 243 273 303 334 364 395 456 546 729 973
0
0
1
99 136 167 197 213 228 243 273 303 334 364 395 456 546 729 973
1
1
1/32 3
4
5
6
6
7
7
8
8
10 10 11 13 15 19 27
2
2
2/32 6
8
10 11 12 13 14 15 17 19 21 23 27 31 42 57
3
3
3/32 9
12 15 18 19 21 22 25 27 31 32 36 42 50 65 88
4
4
4/32 12 16 20 24 26 28 30 32 36 40 44 48 55 65 88 118
5
5
5/32 15 21 26 31 32 35 37 42 46 51 55 61 71 84 111 149
6
6
6/32 18 25 31 36 39 42 45 50 55 61 67 72 84 99 134 179
7
7
7/32 21 30 36 43 46 50 52 59 65 72 78 86 99 118 156 210
8
8
8/32 24 33 41 49 52 56 60 67 74 82 90 97 113 134 179 240
9
9
9/32 28 38 47 55 59 64 68 76 84 93 101 111 128 153 202 271
A
10 10/32 31 42 51 61 66 71 75 84 93 103 113 122 141 168 225 301
B
11 11/32 34 47 57 68 72 78 83 93 103 114 124 135 156 187 248 332
C
12 12/32 37 51 62 73 79 85 91 101 113 124 135 147 170 202 271 362
D
13 13/32 40 55 68 80 86 93 98 111 122 135 147 160 185 221 294 393
E
14 14/32 43 59 72 86 93 99 106 118 132 145 158 172 198 237 317 423
F
15 15/32 46 64 78 93 99 107 113 128 141 156 170 185 214 256 340 454
Notes:
(1) The Vmax factor is an approximation.
(2) In case of motion without acceleration (AccShape = 1) the length of the steps = 1/Vmin. In case of accelerated motion (AccShape = 0) the length of the first step
is shorter than 1/Vmin depending of Vmin, Vmax and Acc.
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