bd4729g ROHM Co. Ltd., bd4729g Datasheet - Page 5

• Manufacturer Part Number: bd4729g
• Description: Bipolar Voltage Detector Ic
• Manufacturer: ROHM Co. Ltd.

●Circuit Applications
1 ）
2 ）
The following is an example of an application circuit using Reset IC for normal power supply detection. BD47 □□ G series requires a
pull up resistor on the output terminal. The pull up resister value should be decided. As the application with enough confirmation of
power supply level and output current capability. When a capacitor has been inserted into the output terminal to delay the output time
or to remove noise, the output will be slower during starting or stopping. Please be careful to select the appropriate pull up resistors,
output current and capacitor when inserting a bypass capacitor between input and GND. Please be aware that if an extremely large
capacitor is used, the response time will become excessively slow.
The following shows an example of adding delay time to a reset signal. It is possible to set the delay time using the capacitor CL and
the resistor RL connected to the output terminal as shown below. At VCC start up, CL will be charged by RL. The CL and RL time
constants and the threshold voltage of the Reset terminal determine the charge delay time. When VCC is decreased, CL is
discharged through the Reset IC. The sum of the respective times plus the delay time of the IC itself becomes the reset signal delay
time.
BD47□□G
V
RESET
(=V
CC
OUT
)
V
V
0V
V
S
Vref
OH
OL
+ΔV
V
V
CC
V
GND
V
S
S
CC
OUT
5
3
GND
V
CC
T
BD47□□G
PLH
Fig.13
5/8
4
R
C
Fig.12
V
L
L
OUT
T
PHL
RESET
V
Reset Pin
DD
●●●●●●●●●●●●
●●●●●●●●●●●●
V
GND
microcontroller
DD
T
PLH
CPU
Micro-controller
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