bd6709fs ROHM Co. Ltd., bd6709fs Datasheet - Page 18

• 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 → DC voltage
conversion circuit.
Adjust the value of resistance
and the capacitor according to
the
frequency of the input signal.
PWM input
Set resistance in consideration
of the input voltage of the
VMIN and VTH terminal.
amplitude
P.23
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.
PWM input
and
the
LAOUT
COSC
OUT1
VMIN
GND
LAIN
RNF
VTH
1
2
3
4
5
6
7
8
LAOUT
COSC
OUT1
VMIN
-
+
GND
LAIN
RNF
VTH
1
2
3
4
5
6
7
8
COSC
LEVEL
AMP
-
+
COSC
LEVEL
AMP
SWITCH
SOFT
+
-
18/40
PWM
COMP
CONTROL
SWITCH
VREF
DRIVER
LOGIC
M
SOFT
+
-
PRE
Vcc
PWM
COMP
CONTROL
PROTECTION
VREF
DRIVER
LOGIC
M
PRE
Vcc
LOCK
TSD
PROTECTION
OUTPUT
SIGNAL
Hall
COMP
Current
Limit
Comp
LOCK
TSD
+
+
-
-
OUTPUT
Hall
COMP
Current
Limit
Comp
SIGNAL
+
+
-
-
AL
FG
VREF
H-
H+
Vcc
CS
OUT2
16
15
14
13
12
10
11
9
AL
FG
VREF
H-
H+
Vcc
CS
OUT2
16
15
14
13
12
10
11
HALL
9
HALL