mc33991dwr2 Freescale Semiconductor, Inc, mc33991dwr2 Datasheet - Page 22

• Manufacturer Part Number: mc33991dwr2
• Description: Gauge Driver Integrated Circuit
• Manufacturer: Freescale Semiconductor, Inc

positions and is accelerating steadily at the maximum
allowed rate. This is critical because it also indicates the
minimum distance the motor must travel while decelerating to
a stop. For example, the stopping distance is also equal to
the current value of n.
• While the motor is stopped, wait until a command is
22
Table 17. Velocity Ramp
33991
TIMING DESCRIPTIONS AND DIAGRAMS
DEVICE FUNCTIONAL DESCRIPTION
Position
Velocity
Note: P
This means: on the nth step, the motor indexed by n
The algorithm to drive the motor is similar to:
received.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
0
1
2
3
4
5
6
7
8
9
n
= n
Time Between
Steps (µs)
16383
6086
2521
1935
1631
1437
1299
1195
1112
1045
988
940
898
861
829
800
773
750
728
708
690
673
657
642
628
0
v
n
=
2
∆
t
(µSteps/s)
n
Velocity
1046.38
1096.77
1144.95
1191.18
1235.68
1278.63
1320.19
1360.48
1399.61
1437.67
1474.76
1510.93
1546.25
1580.79
1614.59
122.08
350.58
480.52
582.15
668.51
744.92
814.19
878.01
937.50
993.43
−
0.00
v
n
−
1
Position
Velocity
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
Time Between
Steps (µs)
363
360
358
355
353
351
348
346
344
342
340
338
336
334
332
330
328
326
324
322
320
319
317
315
314
312
• Send index pulses to the motor at an ever-increasing rate,
in Table 14. This motor’s maximum speed is 4800
microsteps/s (at 12 microsteps/degrees), and its maximum
acceleration is 54000 microsteps/s
to a 1 MHz clock.
according to the time steps in Table 13 until:
or:
An example of the table for a particular motor is provided
(µSteps/s)
Velocity
2771.81
2791.22
2810.50
2829.65
2848.67
2867.56
2886.33
2904.98
2923.51
2941.92
2960.22
2978.41
2996.48
3014.45
3032.31
3050.07
3067.72
3085.27
3102.73
3120.08
3137.34
3154.51
3171.58
3188.56
3205.45
3222.25
• The maximum velocity is reached; at this point
• The distance remaining to travel is less than the
the time intervals stop decreasing
current index in the table. At this point, the
stopping distance is equal to the remaining
distance, ensuring it will stop at the required
position, the motor must begin decelerating.
Position
Velocity
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
Analog Integrated Circuit Device Data
Time Between
Steps (µs)
2
Freescale Semiconductor
. The table is quantized
255
255
254
253
252
251
250
249
249
248
247
246
245
245
244
243
242
241
241
240
239
238
238
237
236
236
(µSteps/s)
Velocity
3931.78
3945.49
3959.15
3972.77
3986.34
3999.86
4013.34
4026.77
4040.16
4053.51
4066.81
4080.06
4093.28
4106.45
4119.58
4132.66
4145.71
4158.71
4171.68
4184.60
4197.49
4210.33
4223.14
4235.91
4248.64
4261.33