AMIS-30624_13 Datasheet, PDF (35/52 Pages) ON Semiconductor – I2C Micro-stepping Motor Driver

AMIS−30624, NCV70624
Table 26. TRUTH TABLE
Condition
Vbemf < Average − DelThr
Vbemf > Average + DelThr
Vbemf < AbsThr
<DelStallLo>
1
0
0
<DelStallHi>
0
1
0
<AbsStall>
0
0
1
<Stall>
1
1
1
By design, the motion will only be detected when the
motor is running at the maximum velocity, not during
acceleration or deceleration.
If the motor is positioning when Stall is detected, an
(internal) hardstop of the motor is generated and the
<StepLoss> and <Stall> flags are set. These flags can
only be reset by sending a GetFullStatus1 command.
If Stall appears during DualPosition then the first phase is
cancelled (via internal hardstop) and after timeout Tstab (see
AC table) the second phase at Vmin starts.
When the <Stall> flag is set the position controller will
generate an internal HardStop. As a consequence also the
<Steploss> flag will be set. The position in the internal
counter will be copied to the <ActPos> register. All flags
can be read out with the GetFullStatus1 command.
Important Remark (limited to motion detection flags /
parameters):
Using GetFullStatus1 will read AND clear the
following flags: <Steploss>, <Stall>, <AbsStall>,
<DelStallLo> and <DelStallHi>. New positioning is
possible and the <ActPos> register will be further updated.
Motion detection is disabled when the RAM registers
<AbsThr[3:0]> and <DelThr[3:0]> are zero. Both
levels can be programmed using the I²C command
SetStallParam in the registers <AbsThr[3:0]> and
<DelThr[3:0]>. Also the OTP register
<AbsThr[3:0]> and <DelThr[3:0]> can be set
using the I²C command SetOTPParam. These values are
copied in the RAM registers during power on reset.
Table 27.
ABSOLUTE AND DELTA THRESHOLD SETTINGS
AbsThr
Index
AbsThr
Level (V) (*)
DelThr
Index
DelThr
Level (V) (*)
0
Disable
0
Disable
1
0.5
1
0.25
2
1.0
2
0.50
3
1.5
3
0.75
4
2.0
4
1.00
5
2.5
5
1.25
6
3.0
6
1.50
7
3.5
7
1.75
8
4.0
8
2.00
9
4.5
9
2.25
A
5.0
A
2.50
B
5.5
B
2.75
C
6.0
C
3.00
D
6.5
D
3.25
E
7.0
E
3.50
F
7.5
F
3.75
(*) Not tested in production. Values are approximations.
MinSamples
<MinSamples[2:0]> is a programmable delay timer.
After the zero crossing is detected, the delay counter is
started. After the delay time−out (t_delay) the back−emf
sample is taken. For more information please refer to the
Application Note “Robust Motion Control with
AMIS−3062x Stepper Motor Drivers”.
Table 28. BACK EMF SAMPLE DELAY TIME
Index
MinSamples[2:0]
t_DELAY (ms)
0
000
87
1
001
130
2
010
174
3
011
217
4
100
261
5
101
304
6
110
348
7
111
391
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