lv8735v ON Semiconductor, lv8735v Datasheet - Page 13

• Manufacturer Part Number: lv8735v
• Description: Bi-cmos Lsi Pwm Constant-current Control Stepping Motor Driver
• Manufacturer: ON Semiconductor

(9) Forward/reverse switching function
(10) Chopping frequency setting
The internal D/A converter proceeds by one bit at the rising edge of the input STEP pulse.
In addition, CW and CCW mode are switched by setting the FR pin.
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.
For constant-current control, this IC performs chopping operations at the frequency determined by the capacitor
(Cchop) connected between the CHOP pin and GND.
The chopping frequency is set as shown below by the capacitor (Cchop) connected between the CHOP pin and GND.
For instance, when Cchop is 200pF, the chopping frequency will be as follows :
Excitation position
1ch output
2ch output
High
Low
Fchop = Ichop/ (Cchop × Vtchop × 2) (Hz)
Fchop = 10μA/ (200pF × 0.5V × 2) = 50kHz
FR
STEP
FR
Ichop : Capacitor charge/discharge current, typ 10μA
Vtchop : Charge/discharge hysteresis voltage (Vtup-Vtdown), typ 0.5V
(1)
(2)
Counter-clockwise (CCW)
CW mode
(3)
Operating mode
Clockwise (CW)
(4)
(5)
LV8735V
(6)
CCW mode
(5)
(4)
(3)
(4)
CW mode
(5)
No.A1848-13/26