MB3773
■ APPLICATION CIRCUIT
EXAMPLE 1 : Monitoring 5V Supply Voltage and Watch-dog Timer
VCC (5V)
MB3773
Logic circuit
1
2
3
4
8
7
6
5
RESET
RESET
CK
CT
GND
• Supply voltage is monitored using Vs.
Detection voltage are VSH and VSL.
EXAMPLE 2 : 5V Supply Voltage Monitoring (external fine-tuning type)
VCC (5V)
MB3773
R1
R2
Logic circuit
1
2
3
4
8
7
6
5
RESET
RESET
CK
CT
GND
• Vs detection voltage can be adjusted externally.
• Selecting R1 and R2 values that are sufficiently lower than the resistance of the IC’s internal
voltage divider allows the detection voltage to be setaccording to the resistance ratio between
R1 and R2. (See the table below.)
R1 (kΩ)
10
R2 (kΩ)
3.9
Detection voltage:VSL (V)
Detection voltage:VSH (V)
4.4
4.1
4.5
4.2
9.1
3.9
10
FUJITSU [ FUJITSU ]
