lv8740v ON Semiconductor, lv8740v Datasheet - Page 10

• Manufacturer Part Number: lv8740v
• Description: Pwm Current Control Stepping Motor Driver
• Manufacturer: ON Semiconductor

Input Pin Function
(1) Chip enable function
(2) Drive mode switching pin function
STM mode (DM = Low or Open)
(1) STEP pin function
(2) Excitation mode setting function
(3) Positional detection monitor function
(4)Constant-current control reference voltage setting function
Positional detection monitor MONI pin is an open drain output. When the excitation position is an initial position, the
MONI output becomes ON.
Please refer to (example of current wave type in each excitation mode).
This IC does the PWM fixed current chopping control of the current of the motor by the automatic operation in setting
the output current. The output current in which a fixed current is controlled by the following calculation type is set by
the resistance connected between the voltage and RF-GND being input to the VREF pin.
The excitation step progresses by inputting the step signal to the STP pin.
The excitation mode of the stepping motor can be set as follows by setting the MD1 pin and the MD2 pin.
VREF input voltage attenuation function
This IC is switched between standby and operating mode by setting the ST pin. In standby mode, the IC is set to
power-save mode and all logic is reset. In addition, the internal regulator circuit and charge pump circuit do not
operate in standby mode.
The IC drive mode is switched by setting the DM pin. In STM mode, stepping motor channel 1 can be controlled by
the CLK-IN input. In DCM mode, DC motor channel 2 or stepping motor channel 1 can be controlled by parallel
input. Stepping motor control using parallel input is 2-phase or 1-2 phase full torque.
This is the initial position of each excitation mode in the initial state after power-on and when the counter is reset.
I OUT =(VREF/5)/RF resistance
*The above-mentioned, set value is an output current of each excitation mode at 100% time.
ATT1
High
High
MD1
Low
High
High
High
High
Low
Low
Low
Low
Low or Open
ST
Low or Open
High
High
ST
DM
Input
ATT2
STP
MD2
High
High
High
High
Low
Low
Low
Low
*
Operating mode
Standby mode
Drive mode
DCM mode
STM mode
Mode
2 phase excitation
1-2 phase excitation (full torque)
1-2 phase excitation
W1-2 phase excitation
Current setting reference voltage attenuation ratio
Excitation mode
Excitation step proceeds
Excitation step is kept
Operating mode
Standby mode
LV8740V
Internal regulator
66.7%
33.3%
100%
50%
Operating
Standby
DC motor channel 2 or stepping motor channel 1 (parallel)
Stepping motor channel 1 (CLK-IN)
Channel 1
100%
100%
100%
100%
Charge pump
Operating
Application
Initial position
Standby
Channel 2
-100%
0%
0%
0%
No.A1864-10/23