A3981KLPTR-T Allegro Microsystems Inc, A3981KLPTR-T Datasheet - Page 26

• Manufacturer Part Number: A3981KLPTR-T
• Description: AUTOMOTIVE PROGRAMMABLE STEPPER DRVR
• Manufacturer: Allegro Microsystems Inc

Specifications of A3981KLPTR-T

• Applications: Stepper Motor Driver, 2 Phase
• Number Of Outputs: 1
• Voltage - Load: 7 V ~ 28 V
• Voltage - Supply: 3 V ~ 5.5 V
• Operating Temperature: -40°C ~ 150°C
• Mounting Type: Surface Mount
• Package / Case: 28-TSSOP (0.173", 4.40mm Width) Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Output: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

A3981
reference value. Although the current in Q3 and Q4 for phase A is
effectively negative, the negation is provided by controlling the
direction of the current. The current control scheme still operates
using positive values.
As shown below, the table of values can be extended to include
Q3 and Q4 with the current direction indicated in the last column.
Note that the same value is now applied to four locations in the
full 360-degree electrical cycle.
Value 0
Value
Value 0
Value
Step
Step
Step 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47
Step
Full 1/2
Table 7. Phase Current Table (default, power-on content)
0
1
0
Step Angle Number
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48
1
5 11 18 23 29 35 40 44 48 52 55 58 60 62 63
5 11 18 23 29 35 40 44 48 52 55 58 60 62 63 63
5 11 18 23 29 35 40 44 48 52 55 58 60 62 63
5 11 18 23 29 35 40 44 48 52 55 58 60 62 63 63
0
1
2
3
4
2
1/4
0
1
2
3
4
5
6
7
8
3
4
1/8 1/16
10
11
12
13
14
15
16
0
1
2
3
4
5
6
7
8
9
5
10
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
11
0
1
2
3
4
5
6
7
8
9
6
7
100.00
100.00
100.00
Phase Current
18.75
29.69
37.50
46.88
56.25
64.06
70.31
76.56
82.81
87.50
92.19
95.31
98.44
98.44
95.31
92.19
87.50
82.81
76.56
70.31
64.06
56.25
46.88
37.50
29.69
18.75
(% of I
A
0.00
9.38
9.38 -100.00
0.00 -100.00
8
9 10 11 12 13 14 15
PMAX
100.00
100.00
-18.75
-29.69
-37.50
-46.88
-56.25
-64.06
-70.31
-76.56
-82.81
-87.50
-92.19
-95.31
-98.44
98.44
95.31
92.19
87.50
82.81
76.56
70.31
64.06
56.25
46.88
37.50
29.69
18.75
-9.38
B
9.38
0.00
)
100.8
107.3
124.2
129.9
135.0
140.1
145.8
151.8
157.9
162.7
169.2
174.6
180.0
Angle
112.1
118.2
Step
10.8
17.3
22.1
28.2
34.2
39.9
45.0
50.1
55.8
61.8
67.9
72.7
79.2
84.6
90.0
95.4
0.0
5.4
A
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Phase
Automotive, Programmable Stepper Driver
B
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Q1 FWD
Q2 FWD
Q3 Rev
Q4 Rev
18
23
29
35
40
44
48
52
55
58
60
62
63
63
63
62
60
58
55
52
48
44
40
35
29
23
18
11
11
A
0
5
5
0
DAC
63
63
62
60
58
55
52
48
44
40
35
29
23
18
11
11
18
23
29
35
40
44
48
52
55
58
60
62
63
63
B
5
0
5
Full 1/2
Shown outlined above, steps 4, 28, 36, and 60 all contain the
value 23.
The other phase, phase B, uses the same values as phase A but
shifted back by 16 Step Angle Numbers. The full distribution of
the value entered in step 4 of phase A is highlighted in figure 12
(and shown in table 7). This single value is used in a total of eight
locations. The same distribution of values applies to all the values
in steps 1 to 15. These values are defined in the A3981 as PT(0)
to PT(14), respectively.
There are two exceptions to this data distribution principal. These
are the zero value and the maximum value:
• The values in phase A steps 0 and 32 and phase B steps 16 and
48 are always set to zero and cannot be programmed.
• The maximum value, PT(15), is distributed to only two Step
Angle Numbers in each phase. These are the points in the cycle
where the peak current is required, namely phase A steps 16 and
48 and phase B steps 0 and 32.
2
3
Step Angle Number
4
5
6
7
0
1/4
10
11
12
13
14
15
8
9
0
1/8 1/16
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
0
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47 -100.00
48 -100.00
49 -100.00
50
51
52
53
54
55
56
57
58
59
60
61
62
63
0
Phase Current
-18.75
-29.69
-37.50
-46.88
-56.25
-64.06
-70.31
-76.56
-82.81
-87.50
-92.19
-95.31
-98.44
-98.44
-95.31
-92.19
-87.50
-82.81
-76.56
-70.31
-64.06
-56.25
-46.88
-37.50
-29.69
-18.75
(% of I
-9.38 -100.00
-9.38
0.00 -100.00
0.00
A
115 Northeast Cutoff
1.508.853.5000; www.allegromicro.com
Allegro MicroSystems, Inc.
Worcester, Massachusetts 01615-0036 U.S.A.
PMAX
100.00
100.00
-98.44
-95.31
-92.19
-87.50
-82.81
-76.56
-70.31
-64.06
-56.25
-46.88
-37.50
-29.69
-18.75
18.75
29.69
37.50
46.88
56.25
64.06
70.31
76.56
82.81
87.50
92.19
95.31
98.44
-9.38
B
0.00
9.38
)
180.0
185.4
190.8
197.3
202.1
208.2
214.2
219.9
225.0
230.1
235.8
241.8
247.9
252.7
259.2
264.6
270.0
275.4
280.8
287.3
292.1
298.2
304.2
309.9
315.0
320.1
325.8
331.8
337.9
342.7
349.2
354.6
Angle
Step
0.0
A
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
Phase
B
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
18
23
29
35
40
44
48
52
55
58
60
62
63
63
63
62
60
58
55
52
48
44
40
35
29
23
18
11
11
A
0
5
5
0
DAC
63
63
62
60
58
55
52
48
44
40
35
29
23
18
11
11
18
23
29
35
40
44
48
52
55
58
60
62
63
63
B
5
0
5
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