Using the LV8741V PWM current-control stepping motor driver IC can be designed a very simple and efficiency DC motor driver electronic project .
As you can see in the circuit diagram, this electronic project require few external electronic parts . The maximum output current that can be provided by this PWM current-control stepping motor driver IC is up to 1.5 ampere .
The reference voltage is set by the voltage applied to the VREF pin and the two inputs ATT1 and ATT2. The output current (output current at a constant-current drive current ratio of 100%) can be set from this reference voltage and the RF resistance value.
To protect the IC from damage due to short-circuit of the output caused by lightening or ground fault, the output short-circuit protection circuit to put the output in standby mode and turn on the alarm output is incorporated. Note that when the RF pin is short-circuited to GND, this output short-circuit protection is not effective against shorting to power.
When the output current is below the output short-circuit protection current, the output is controlled by the input signal.
When the ST pin is set High, the charge pump circuit operates and the VG pin voltage is boosted from the VM voltage to the VM + VREG5 voltage. If the VG pin voltage is not boosted sufficiently, the output cannot be controlled, so be sure to provide a wait time of tONG or more after setting the ST pin High before starting to drive the motor. When controlling the stepping motor driver with the CLK-IN input, set the ST pin High, wait for the tONG time duration or longer, and then set the OE pin High. In addition, when controlling the stepping motor and DC motor driver with parallel input, set the ST pin High, wait for the tONG time duration or longer, and then start the control for each channel.
The setting conditions for the above PWM current-control DC motor driver circuit diagram are as follows : Auto recovery-type output short-circuit protection function (EMM = Low), Output enable function fixed to output ON state (OE = High), Current limit reference voltage setting = 100% (ATT1 = Low, ATT2 = Low) ,Chopping frequency : 37kHz (RCHOP = 43k ).
Voltages required by this LV8741V current-control DC motor driver are from 9.5 to 35 volt for motor power and from 2.7 to 5.5 for logic power supply .