HA16117F Datasheet, PDF (4/31 Pages) Hitachi Semiconductor – CMOS Watchdog Timer

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 I₂ in the multivibrator, the higher the duty cycle of the watchdog filter
output, the shorter the time during which I₂ discharges C_R. If the duty cycle is high enough then C_R 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 HA16117FPA/FPB/FPC HA16117FPAJ/FPBJ/FPCJ Unit
Power supply voltage
V_CC
–0.3 to +14
–0.3 to +14
V
P-RUN input voltage
V_P
V_CC
V_CC
V
ACC input voltage
V_ACC
14
14
V
RES output current
I _RES
10
10
mA
Permissible dissipation *¹
P_T
300
300
mW
Operating temperature range Topr
–30 to +85
–40 to +85
°C
Storage temperature
Tstg
–55 to +125
–55 to +125
°C
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.
40mm
Substrate
0.8 mm ceramic or
1.5 mm epoxy
400
83°C
300
−7.14 mW/°C
200
(30% wiring density)
100
0
−30 −20 0
85°C
20 40 60 80 100
Ambient operating temperature range Ta (°C)
4