MB3771PF-G-BND-JNE1 Datasheet, PDF (13/21 Pages) Fujitsu Component Limited. – ASSP For power supply applications BIPOLAR Power Supply Monitor

MB3771
11. Low Voltage and Over Voltage Detection (VCC = 5 V)
VSH has no hysteresis. When over voltage is detected, RESET is held in the constant time as well as when
low voltage is detected.
VSL = (R1 + R2) × VSB/R2
VSH = (R3 + R4) × VSC/R4
VCC
RESET
R3
R4
CT
MB3771
1
8
2
7
3
6
4
5
R1
RESET
R2
VCC
VSL
VSH
12. Detection of Abnormal State of Power Supply System (VCC = 5 V)
• This Example circuit detects abnormal low/over voltage of power supply voltage and is indicated by LED
indicator. LED is reset by the CLEAR key.
• The detection levels of low/over voltages are determined by VSA, and R1 and R2 respectively.
VCC
R1
R2
MB3771
1
8
2
7
3
6
4
5
LED
R3: 620 Ω
R4:
1 kΩ to 100 kΩ
CLEAR
13