AMIS-30624 I2C Microstepping Motordriver
Data Sheet
Value Table:
Table 25: Absolute Threshold Settings
Table 26: Delta Threshold Settings
DelThr
Index
AbsThr Index
AbsThr Level (V)
DelThr Level (V)
0
1
2
3
4
5
6
7
8
9
A
B
C
D
E
F
Disable
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
6.5
7.0
7.5
0
1
2
3
4
5
6
7
8
9
A
B
C
D
E
F
Disable
0.25
0.50
0.75
1.00
1.25
1.50
1.75
2.00
2.25
2.50
2.75
3.00
3.25
3.50
3.75
MinSamples
MinSamples[2:0] is a Bemf sampling delay time expressed in number of PWM cycles, for more information please refer to the white
paper “Robust Motion Control with AMIS-3062x Stepper Motor Drivers”.
Table 27: Back emf Sample Delay Time
tDELAY (µs)
Index
MinSamples[2:0]
PWMfreq = 0
PWMfreq = 1
0
1
2
3
4
5
6
7
000
001
010
011
100
101
110
111
87
43
65
87
109
130
152
174
196
130
174
217
261
304
348
391
FS2StallEn
If AbsThr or DelThr <>0 (i.e. motion detection is enabled), then stall detection will be activated AFTER the acceleration ramp + an
additional number of full-steps, according to the following table:
Table 28: Activation Delay of Motion Detection
Index
FS2StallEn[2:0]
Delay (Full Steps)
0
1
2
3
4
5
6
7
000
001
010
011
100
101
110
111
0
1
2
3
4
5
6
7
For more information please refer to the white paper “Robust Motion Control with AMIS-3062x Stepper Motor Drivers”.
DC100StEn
When a motor with large back – e.m.f. is operated at high velocity and low supply voltage, then the PWM duty cycle can be as high as
100 percent. This indicates that the supply is too low to generate the required torque and might also result in erroneously triggering the
stall detection. The bit “DC100StEn” (Bit 1 in Data 7 of SetStallParam) enables the function where stall detection is switched off
when PWM duty cycle equals 100 percent. For more information the white paper “Robust Motion Control with AMIS-3062x Stepper
Motor Drivers”.
Motion Qualification Mode
This mode is useful to debug motion parameters and to verify the stability of stepper motor systems. The motion qualification mode is
entered by means of the I2C command TestBemf. The SWI pin will be converted into an analog output on which the Bemf integrator
output can be measured. Once activated, it can only be stopped after a POR. During the back emf observation, reading of the SWI
state is internally forbidden. More information is available in the white paper “Robust Motion Control with AMIS-3062x Stepper Motor
Drivers”.
AMI Semiconductor – Apr. 2007, Rev 3.1, M-20664-003
38
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