HA16117F Series
Watchdog Timer
Reshapes the P-RUN signal (programming-running pulse) from the MPU to obtain a 50% duty cycle, then
converts frequency to duty cycle in the watchdog filter (WD filter).
The watchdog filter is a bandpass filter. The duty cycle of the filter output is highest in the normal
frequency range of P-RUN.
The watchdog filter output controls I in the multivibrator, the higher the duty cycle of the watchdog filter
2
output, the shorter the time during which I2 discharges CR. If the duty cycle is high enough then CR is held
at a high potential, preventing the multivibrator from firing, and the RES output remains high.
Absolute Maximum Ratings (Ta = 25°C)
Ratings
Item
Symbol
VCC
HA16117FPA/FPB/FPC
HA16117FPAJ/FPBJ/FPCJ Unit
Power supply voltage
P-RUN input voltage
ACC input voltage
RES output current
Permissible dissipation *1
–0.3 to +14
VCC
–0.3 to +14
VCC
V
VP
V
VACC
IRES
14
14
V
10
10
mA
mW
°C
°C
PT
300
300
Operating temperature range Topr
Storage temperature Tstg
–30 to +85
–55 to +125
–40 to +85
–55 to +125
Note: 1. This is the value when mounted on a glass epoxy substrate with 30% wiring density, up to an
ambient temperature of 83°C. Above that temperature, derate by 7.14 mW/°C.
Substrate
40mm
0.8 mm ceramic or
1.5 mm epoxy
400
300
200
100
0
83°C
−7.14 mW/°C
(30% wiring density)
85°C
20 40 60 80 100
Ambient operating temperature range Ta (°C)
−30 −20
0
4
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