FAN8001 Fairchild Semiconductor, FAN8001 Datasheet - Page 9

• Manufacturer Part Number: FAN8001
• Description: 5-Channel Motor Driver
• Manufacturer: Fairchild Semiconductor

5. LOADING MOTOR SPEED CONTROL
• If the torque of the loading motor is too low with the pin #20 open, then use it as the above diagram.
• The desired torque could be obtained by selecting the appropriate resistor R as shown in the left diagram.
• If it is necessary, the zener diode can be used as in the right diagram.
• The maximum torque is obtained when the applied voltage at pin #20 is about 6.8V (at V
6. DRIVER (EXCEPT FOR LOADING MOTOR DRIVER)
• The voltage, V
• The input signal through the pin #3 is amplified by 10k/10k times and then fed to the level shift.
• The level shift produces the current due to the difference between the input signal and the arbitrary reference signal. The
• Driver Buffer operates the power TR of the output stage according to the state of the input signal.
• The output stage is the BTL Driver and the motor is rotating in forward direction by operating TR Q1 and TR Q4. On the
• When the input voltage through the pin #3 is below the V
• When the input voltage through the pin #3 is above the V
• If it is desired to change the gain, then the pin #4 or #24 can be used.
current produced as + I and
other hand, if TR Q2 and TR Q3 is operating, the motor is rotating in reverse direction.
19
3
4
10
25
24
VREF
(2.5V)
100k
10k
REF
V
CC
, is the reference voltage given by the bias voltage of the pin #23.
4V
(8V)
10k
+
AMP
I is fed into the driver buffer.
Level
shift
50k
50k
20
V
CC
R
+ I
I
REF
REF
+
+
9
, the motor rotates reverse direction.
, the motor rotates forward direction.
Buffer
Buffer
V
CC
4V
(8V)
Q1
Q3
17
11
27
1
V
CC
=8V).
50k
50k
M
20
V
+ V
18
12
26
CC
2
R
D
Q2
Q4
FAN8001D