L6482
Functional description
Doc ID 023768 Rev 1
21/73
6.4.1 Automatic
Full-step and Boost modes
When motor speed is greater than a programmable full-step speed threshold, the L6482
switches automatically to Full-step mode; the driving mode returns to microstepping when
motor speed decreases below the full-step speed threshold.
The switching between the microstepping and Full-step mode and vice versa is always
performed at an electrical position multiple of
π
/4 (
).
Full-step speed threshold is set through the related parameter in the FS_SPD register
(
).
When the BOOST_MODE bit of the FS_SPD register is low (default), the amplitude of the
voltage squarewave in Full-step mode is equal to the peak of the voltage sinewave multiplied
by sine(
π
/4) (
). This avoids the current drop between the two driving modes.
When the BOOST_MODE bit of the FS_SPD register is high, the amplitude of the voltage
squarewave in Full-step mode is equal to the peak of the voltage sinewave (
). That
improves the output current increasing the maximum motor torque.
Figure 6.
Automatic Full-step switching in Normal mode
Ph
as
e A
Ph
as
e B
(2N+1) x
π
/4
(2N+1) x
π
/4
F
u
ll-
S
tep
Micro
s
tepping
Micro
s
tepping
V
pe
a
k
s
in(
π
/4 )x V
pe
a
k
AM150
3
6v1
