AMIS-30421 Datasheet, PDF (31/41 Pages) ON Semiconductor – Micro-Stepping Stepper Motor Bridge Controller

AMIS−30421
Control Register 0 (CR0)
Control Register 0 is located at address 0x01 and is used to set the maximum coil current and stepping mode. It’s also used
to set the “coil current zero crossing” duration.
Table 11. CONTROL REGISTER 0
Address
0x01
Access
Reset
Data
Bit 7
R/W
0
Control Register 0 (CR0)
Bit 6
Bit 5
Bit 4
Bit 3
R/W
R/W
R/W
R/W
0
0
0
0
SM[2:0]
MIN_SLA_TIME[1:0]
Bit 2
R/W
0
Bit 1
R/W
0
CUR[2:0]
Bit 0
R/W
0
Table 12. CONTROL REGISTER 0 PARAMETERS
Parameter
SM[2:0]
Value
000
001
010
011
100
Value
64^th
32^nd
16^th
8^th
4^th
101
Half step compensated
110 Half step uncompensated
111
Full Step
00
40 ms
01
MIN_SLA_TIME[1:0]
10
120 ms
200 ms
11
360 ms
000
100 mV
001
135 mV
010
200 mV
011
CUR[2:0]
100
270 mV
335 mV
101
400 mV
110
500 mV
111
600 mV
Description
Defines the 8 stepping modes for the PWM regulator.
Defines the minimum “coil current zero crossing” duration.
Remark: when NXT frequency gets above PWM frequency
(f_PWM), MIN_SLA_TIME could be 40us longer.
Defines the maximum voltage over the coil current sense
resistor which defines the maximum coil current.
The maximum coil current is calculated as next:
I_coil = CUR[2:0] / R_sense
Info
p19
p20
p20
Control Register 1 (CR1)
Control Register 1 is located at address 0x02 and can used to set the direction, NXT−pin polarity, output configuration of
WDb−, ERRb− and DO−pin and to enable PWM jitter. It can also be used to set an additional delay between switching off and
on MOSFET’s of one half H−bridge (to prevent a short circuit).
Table 13. CONTROL REGISTER 1
Address
0x02
Access
Reset
Data
Bit 7
R/W
0
DIRCTRL
Control Register 1 (CR1)
Bit 6
Bit 5
Bit 4
R/W
R/W
R/W
0
0
1
NXTP
−
IO_OT
Bit 3
R/W
0
−
Bit 2
R/W
0
PWMJ
Bit 1
Bit 0
R/W
R/W
0
1
NO_CROSS[1:0]
http://onsemi.com
31