bd6709fs ROHM Co. Ltd., bd6709fs Datasheet - Page 20

• Manufacturer Part Number: bd6709fs
• Description: Dc Brushless Motor Drivers For Cooling Fans Speed Controllable Single-phase Full-wave Dc Brushless Fan Motor Drivers
• Manufacturer: ROHM Co. Ltd.

PWM signal can be input directly.
Become direct pulse input mode
by pulling up VTH terminal to
VCC.
2) Pulse input application 1
3) Pulse input application 2
The example of an application for converting external PWM signal into the DC voltage, and controlling the rotational
speed. Minimum rotational speed can be set.
The example of an application for controlling the rotational speed by DUTY of external PWM signal. The minimum
rotational speed cannot be set.
P.23
P.23
PWM signal → DC voltage
conversion circuit.
Adjust the value of resistance
and the capacitor according to
the
frequency of the input signal.
amplitude
PWM INPUT
and
the
Vcc line
COSC
VMIN
GND
RNF
VTH
A1H
A1L
Vcc
1
2
3
4
5
6
7
8
POW
Vcc line
DRIVER
COSC
COSC
PRE
VMIN
GND
PWM COMP
VTH
RNF
A1H
A1L
Vcc
1
2
3
4
5
6
7
8
+
-
POW
POW
SWITCH
START
SOFT
SOFT
20/40
DRIVER
COSC
PRE
PWM COMP
CONTROL
+
LOGIC
-
VREF
POW
VM line
SWITCH
START
SOFT
SOFT
PROTECTION
LOCK
VREF line
TSD
Current Limit
Hall COMP
CONTROL
Comp
LOGIC
VREF
OUTPUT
SIGNAL
VM line
PROTECTION
+
+
-
-
LOCK
TSD
Current Limit
Hall COMP
Comp
OUTPUT
SIGNAL
AL
FG
VREF
H-
H+
CS
A2H
A2L
16
15
14
13
12
11
10
9
+
+
-
-
HALL
AL
FG
VREF
H-
H+
CS
A2H
A2L
16
15
14
13
12
10
11
9
HALL