MB3793 Datasheet, PDF (13/20 Pages) Fujitsu Component Limited. – POWER-VOLTAGE MONITORING IC WITH WATCHDOG TIMER

MB3793-42/30
2. AC Characteristics
Parameter
(VCC = +5 V (MB3793-42), VCC = +3.3 V (MB3793-30), Ta = +25°C)
Symbol
Test Conditions
Min.
Limits
Unit
Typical Max.
Power-on reset hold time
MB3793-42
tPR
CTP = 0.1 µF
MB3793-30
80
130
180 ms
30
75
120 ms
MB3793-42
CTW = 0.01 µF
Watchdog timer monitoring time
tWD
MB3793-30
CTP = 0.1 µF
7.5
15
22.5 ms
8
16
24 ms
Watchdog timer reset time
MB3793-42
tWR CTP = 0.1 µF
MB3793-42
5
10
15 ms
2.0
5.5
9 ms
Clock (CK1, CK2) input pulse duration
tCKW
-
500
-
-
ns
Reset (RESET) output transition
time*
Rising
Falling
tTLH CL = 50pF
tTHL CL = 50pF
-
-
500 ns
-
-
500 ns
*The voltage range is 10% to 90% at testing the reset output transition time.
s WATCHDOG TIMER USE EXAMPLE
1. Monitoring Two Clocks
VCC
CTW CTP
(2) CTW
(5)
VCC
RESET ⁽¹⁾
(3) CTP
MB3793
CK1 (8)
INH GND
(6) (4)
CK2 (7)
RESET VCC
Microprocessor 1
CK
GND
RESET ^VCC
Microprocessor 2
CK
GND
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