L6472 STMICROELECTRONICS [STMicroelectronics], L6472 Datasheet - Page 44

• Manufacturer Part Number: L6472
• Description: dSPIN fully integrated microstepping motor driver
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

Programming manual
9.1.9
9.1.10
44/69
FS_SPD
The FS_SPD register contains the threshold speed. When the actual speed exceeds this
value the step mode is automatically switched to full-step two-phase on. Its value is
expressed in step/tick (format unsigned fixed point 0.18) and to convert it in step/s the
following formula can be used.
Equation 6
If the FS_SPD value is set to hFF (max.) the system always works in microstepping mode
(SPEED must go beyond the threshold to switch to full-step mode). Setting FS_SPD to zero
does not have the same effect as setting step mode to full-step two phase on: the zero
FS_SPD value is equivalent to a speed threshold of about 7.63 step/s.
The available range is from 7.63 to 15625 step/s with a resolution of 15.25 step/s.
TVAL_HOLD, TVAL_RUN, TVAL_ACC and TVAL_DEC
The TVAL_HOLD register contains the current value that is assigned to the torque
regulation DAC when the motor is stopped.
The TVAL_RUN register contains the current value that is assigned to the torque regulation
DAC when the motor is running at constant speed.
The TVAL_ACC register contains the current value that is assigned to the torque regulation
DAC during acceleration.
The TVAL_DEC register contains the current value that is assigned to the torque regulation
DAC during deceleration.
The available range is from 31.25 mA to 4 A with a resolution of 31.25 mA, as shown in
Table
Table 12.
0
0
1
1
12.
0
0
1
1
Torque regulation by TVAL_HOLD, TVAL_ACC, TVAL_DEC and
TVAL_RUN registers
0
0
1
1
TVAL_X [6..0]
0
0
1
1
0
0
1
1
[
Doc ID 022729 Rev 1
step
0
0
1
1
⁄
s
]
=
0
1
0
1
(
---------------------------------------------------------- -
FSSPD
tick
+
0.5
)
Output current amplitude
⋅
2
–
18
31.25 mA
62.5 mA
3.969 A
4 A
L6472