ST L6470H User Manual

L6470 Programming manual
Doc ID 16737 Rev 2 41/64
9.1.11 INT_SPEED
The INT_SPEED register contains the speed value at which the BEMF compensation curve
changes slope (see paragraph
7.4 for details). Its value is expressed in step/tick and to
convert it in [step/s] the following formula can be used:
Equation 9
where INT_SPEED is the integer number stored into the register and tick is 250 ns.
The available range is from 0 to 3906 step/s with a resolution of 0.238 step/s.
Any attempt to write the register when the motor is running causes the command to be
ignored and the NOTPERF_CMD flag to rise (see paragraph
9.1.22).
9.1.12 ST_SLP
The ST_SLP register contains the BEMF compensation curve slope that is used when the
speed is lower than the intersect speed (see paragraph
7.4 for details). Its value is
expressed in s/step and the available range is from 0 to 0.004 with a resolution of 0.000015.
When ST_SLP, FN_SLP_ACC and FN_SLP_DEC parameters are set to zero no BEMF
compensation is performed.
Any attempt to write the register when the motor is running causes the command to be
ignored and the NOTPERF_CMD flag to rise (see paragraph
9.1.22).
9.1.13 FN_SLP_ACC
The FN_SLP_ACC register contains the BEMF compensation curve slope that is used when
the speed is greater than the intersect speed during acceleration (see paragraph
7.4 for
details). Its value is expressed in s/step and the available range is from 0 to 0.004 with a
resolution of 0.000015.
When ST_SLP, FN_SLP_ACC and FN_SLP_DEC parameters are set to zero no BEMF
compensation is performed.
Any attempt to write the register when the motor is running causes the command to be
ignored and the NOTPERF_CMD flag to rise (see paragraph
9.1.22).
Table 11. Voltage amplitude regulation registers
KVAL_X [7..0] Output voltage
00000000 0
00000001 V
S
x (1/256)
… … … … … … … … …
11111110 V
S
x (254/256)
11111111 V
S
x (255/256)
[]
tick
2SPEED_INT
s/step
24−
⋅
=

ST L6470H Specifications

General

Brand	ST
Model	L6470H
Category	Computer Hardware
Language	English