LV8727 Datasheet, PDF (9/23 Pages) Sanyo Semicon Device – PWM Current Control Stepping Motor Driver

LV8727
(8) Forward / reverse switching function
FR
Operating mode
Low
Clockwise (CW)
High
Counter-clockwise (CCW)
FR
STEP
CW mode
CCW mode
CW mode
Excitation position
(1) (2) (3) (4) (5) (6) (5) (4) (3) (4) (5)
1ch output
2ch output
The internal D/A converter proceeds by a bit on the rising edge of the step signal input to the STEP pin. In addition,
CW and CCW mode are switched by FR pin setting.
In CW mode, the channel 2 current phase is delayed by 90° relative to the channel 1 current.
In CCW mode, the channel 2 current phase is advanced by 90° relative to the channel 1 current.
(9) DECAY mode setting
Current DECAY method is selectable as shown below by applied voltage to the FDT pin.
FDT voltage
3.5V to
1.1V to 3.1V or OPEN
To 0.8V
DECAY method
SLOW DECAY
MIXED DECAY
FAST DECAY
(10) Chopping frequency setting function
Chopping frequency is set as shown below by a capacitor between OSC1 pin and GND.
Fcp = 1 / ( Cosc1 / 10 х 10^-6 ) (Hz)
(Example) When Cosc1 = 180pF, the chopping frequency is shown below.
Fcp = 1 / ( 180 х 10^-12 / 10 х 10^-6 ) = 55.6(kHz)
No.A1998-9/23