tb6641fg TOSHIBA Semiconductor CORPORATION, tb6641fg Datasheet - Page 11

• Manufacturer Part Number: tb6641fg
• Description: Full-bridge Dc Motor Driver Ic
• Manufacturer: TOSHIBA Semiconductor CORPORATION

7. Direct PWM Control
The motor rotation speed is controllable by the PWM input sent through the PWM pin.
It is also possible to control the motor rotation speed by sending in the PWM signal through not the PWM
pin but the IN1 and IN2 pins.
When the motor drive is controlled by the PWM input, the TB6641FG repeats operating in Normal
Operation mode and Short Brake mode alternately.
For preventing the shoot-through current in the output circuit caused by the upper and lower power
transistors being turned on simultaneously, the dead time is internally generated at the time the upper and
lower power transistors switches between on and off.
This eliminates the need of inserting Off time externally; thus the PWM control with synchronous
rectification is enabled.
Note that inserting Off time externally is not required on operation mode changes between CW and CCW,
and CW (CCW) and Short Brake, again, because of the dead time generated internally.
OUT1
PWM ON
M
t1
Output voltage
waveform
(OUT1)
OUT1
PWM OFF  ON
t4 = 500 ns (typ.)
VM
GND
M
OUT1
t1
t2
VM
GND
PWM ON  OFF
t2 = 200 ns (typ.)
t3
11
M
OUT1
t4
t5
VM
GND
PWM ON
t5
M
OUT1
VM
GND
RSGND
VM
PWM OFF
M
t3
TB6641FG
2011-06-21
VM
GND