AMIS-30624 Datasheet, PDF (36/56 Pages) AMI SEMICONDUCTOR – I2C Microstepping Motordriver

AMIS-30624
Value Table:
Table 25: Absolute Threshold Settings
AbsThr Index AbsThr Level (V)
0
Disable
1
0.5
2
1.0
3
1.5
4
2.0
5
2.5
6
3.0
7
3.5
8
4.0
9
4.5
A
5.0
B
5.5
C
6.0
D
6.5
E
7.0
F
7.5
Table 26: Delta Threshold Settings
DelThr
Index
DelThr Level (V)
0
Disable
1
0.25
2
0.50
3
0.75
4
1.00
5
1.25
6
1.50
7
1.75
8
2.00
9
2.25
A
2.50
B
2.75
C
3.00
D
3.25
E
3.50
F
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
Index
MinSamples[2:0]
0
000
1
001
2
010
3
011
4
100
5
101
6
110
7
111
PWMfreq = 0
87
130
174
217
261
304
348
391
t_DELAY (μs)
PWMfreq = 1
43
65
87
109
130
152
174
196
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
000
0
1
001
1
2
010
2
3
011
3
4
100
4
5
101
5
6
110
6
7
111
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”.
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