STMicroelectronics Fully integrated stepper motor driver mounting the L6472 in a high power PowerSO package EVAL6472PD EVAL6472PD Data Sheet
Product codes
EVAL6472PD
Functional description
L6472
26/70
DocID022729 Rev 3
The HardStop command stops the motor instantly, ignoring deceleration constraints and
maintaining the rotor position (a holding torque is applied).
maintaining the rotor position (a holding torque is applied).
The SoftHiZ command causes the motor to decelerate with a programmed deceleration
value until the MIN_SPEED value is reached and then forces the bridges into high-
impedance state (no holding torque is present).
value until the MIN_SPEED value is reached and then forces the bridges into high-
impedance state (no holding torque is present).
The HardHiZ command instantly forces the bridges into high-impedance state (no holding
torque is present).
torque is present).
6.7.5 Step-clock
mode
In step-clock mode the motor motion is defined by the step-clock signal applied to the STCK
pin.
pin.
At each step-clock rising edge, the motor is moved by one microstep in the programmed
direction and the absolute position is consequently updated.
direction and the absolute position is consequently updated.
When the system is in step-clock mode the SCK_MOD flag in the STATUS register is raised,
the SPEED register is set to zero and the motor status is considered stopped whatever the
STCK signal frequency (the MOT_STATUS parameter in the STATUS register equal to
g00h).
the SPEED register is set to zero and the motor status is considered stopped whatever the
STCK signal frequency (the MOT_STATUS parameter in the STATUS register equal to
g00h).
6.7.6
GoUntil and ReleaseSW commands
In most applications the power-up position of the stepper motor is undefined, so an
initialization algorithm driving the motor to a known position is necessary.
initialization algorithm driving the motor to a known position is necessary.
) to easily initialize the motor position.
The GoUntil command makes the motor run at the target constant speed until the SW input
is forced low (falling edge). When this event occurs, one of the following actions can be
performed:
is forced low (falling edge). When this event occurs, one of the following actions can be
performed:
ABS_POS register is set to zero (home position) and the motor decelerates to zero
speed (as a SoftStop command)
speed (as a SoftStop command)
ABS_POS register value is stored in the MARK register and the motor decelerates to
zero speed (as a SoftStop command).
zero speed (as a SoftStop command).
If the SW_MODE bit of the CONFIG register is set to e0f, the motor does not decelerate but
it immediately stops (as a HardStop command).
it immediately stops (as a HardStop command).
The ReleaseSW command makes the motor run at the programmed minimum speed until
the SW input is forced high (rising edge). When this event occurs, one of the following
actions can be performed:
the SW input is forced high (rising edge). When this event occurs, one of the following
actions can be performed:
ABS_POS register is set to zero (home position) and the motor immediately stops
(as a HardStop command)
(as a HardStop command)
ABS_POS register value is stored in the MARK register and the motor immediately
stops (as a HardStop command).
stops (as a HardStop command).
If the programmed minimum speed is less than 5 step/s, the motor is driven at 5 step/s.