HA16117F Datasheet, PDF (9/31 Pages) Hitachi Semiconductor – CMOS Watchdog Timer

HA16117F Series
2. With a low-frequency P-RUN signal ( 13 Hz to 26 Hz)
When f_P-RUN is 13 Hz to 26 Hz, the WD duty (D = 100 × t₂/2T) is 25% to 50%. When the WD
duty is 25% or above, multivibrator (power-on and auto-reset circuit) oscillation stops. As a
result, the RES signal is fixed high.
H
P-RUN
L
H
Q
L
H
Q
L
H
A
L
5V
3.6 V
C_F
0.9 V
0V
H
WD
L
5V
40 ms (25 Hz)
2T
t₁ 5 µs
t₂
33 ms
3.2 V
C_R
1.6 V
0V
H
B
L
H
C
L
H
RES
L
60 ms
20 ms
9