HA16117F Datasheet, PDF (12/31 Pages) Hitachi Semiconductor – CMOS Watchdog Timer

HA16117F Series
5. t_OFF when P-RUN signal 90 kHz
When the P-RUN frequency is high, even though within specification, the C_R pin potential
falls. If the P-RUN frequency falls sharply at this time, t_OFF may be short.
With values of C_F = 0.01 µF and C_R = 0.1 µF, the C_R pin potential will not fall as long as the
P-RUN frequency is 20 kHz or below.
P-RUN
Q
Q
A
C_F
WD
H
L
H
L
H
L
H
L
5V
3.6 V
0.9 V
0V
H
L
5V
3.2 V
C_R
1.6 V
0V
H
B
L
H
C
L
H
RES
L
f_{P_RUN} ≈ 90 kHz
50 ms
≈ 2.3 V
t_OFF
26 ms
12