MB3793 Datasheet, PDF (5/20 Pages) Fujitsu Component Limited. – POWER-VOLTAGE MONITORING IC WITH WATCHDOG TIMER

s STANDARD CONNECTION
VCC
MB3793-42/30
CTW
CTP
CTW
VCC
RESET
CTP
MB3793
CK1
CK2
INH GND
RESET VCC
Microprocessor 1
CK
GND
RESET VCC
Microprocessor 2
CK
GND
Equation of time-setting capacitances (CTP and CTW) and set time
tPR (ms) ≈ A x CTP (µF)
tWD (ms) ≈ B x CTW (µF) + C x CTP (µF)
However, when —C^T—^P ≤ about 10,
CTW
tWD (ms) ≈ B x CTW (µF)
tWR (ms) ≈ D x CTP (µF)
Model No.
MB3793-42
MB3793-30
A
1300
750
Values of A, B, C, and D
B
C
D
1500
3
100
1600
4
55
Remark
(Example) When CTP = 0.1 µF and CTW = 0.01 µF,
• MB3793-42
tPR ≈ 130 [ms]
tWD ≈ 15 [ms]
tWR ≈ 10 [ms]
• MB3793-30
tPR ≈ 75 [ms]
tWD ≈ 16 [ms]
tWR ≈ 5.5 [ms]
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