LB11861MC-AH Datasheet, PDF (4/5 Pages) ON Semiconductor – Single-Phase Full-Wave Fan Motor Driver

Block Diagram
LB11861MC
FG
VCC
Thermal
protection circuit
constant
voltage
HALL
IN+
IN-
Amplifier with
hysteresis
control
circuit
charge/discharge
circuit
Delay circuit
Delay circuit
SGND
CT
PWM-IN
PGND
OUT2
M
OUT1
Application Circuit Example
*2
VCC
PWM control signal
H IN-
*4
IN+
FG
*5
OUT1
f=16K to 50KHz
*3
CT=0.47 to 1uF
OUT2
PWM-IN
PGND
*1
CT
SGND
*1. Power supply and ground lines
P-GND is connected to the motor power supply system and S-GND is connected to the control circuit power supply system.
These two systems should be formed from separate lines and the control system external components should be connected to
S-GND.
*2. Regeneration power supply stabilization capacitor
The capacitor CM provides power supply stabilization for both PWM drive and kickback absorption. A capacitor with a value of
over 1 to 10µF is used for CM. Insert the zenor diode for kickback protection between VCC and GND. Since this IC adopts a
technique in which switching is performed by the high side transistor and regeneration is handled by the low side transistor, the
pattern connecting CM to VM and P-GND must be as wide and as short as possible.
*3. PWM-IN pin
This is for speed control with the external PWM signal. With driving at the input of “H” and regeneration (Slow-Decay) at the
input of “L”, high efficiency rotation control can be made. RP=10kΩ is the current limiting resistor for protection. Though the
input signal frequency range is 0 to 50 kHz, 16 k to 50 kHz is recommended. Rotation can be stopped by inputting “L”.
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