S-19400 Datasheet, PDF (22/36 Pages) Seiko Instruments Inc – Watchdog operation voltage range

FOR AUTOMOTIVE 125°C OPERATION LOW CURRENT CONSUMPTION WATCHDOG TIMER WITH RESET FUNCTION
S-19400/19401 Series
Rev.2.1_00
7. Operation of low voltage detection
The voltage detection circuit_{__}d_{__}e_{_}t_{_}e_{__}cts a low volta_{_}g_{__}e_{___}i_{_}f the power supply voltage falls below the detection voltage, and
then "L" is output from the WDO pin and the RST pin (Only the S-19401 Series). The output is maintained until
the charge-discharge operation of the CPOR pin is performed 4 times.
The S-19400/19401 Series can detect a low voltage even if either the _{_}C_{__}POR pin or the WDT pin performs the
charge-discharge operation. In this case, the status of the WEN pin or the W / T pin does not have an affect.
VDD
CPOR
CWDT
12
1234
1234
1234
12
WDI
"H" or "L"
W/T
(S-19400 only)
WEN
(Active "H")
"H" or "L"
"H" or "L"^*1
WDO
RST
(S-19401 only)
Figure 38
*1. When the WEN pin is Disable, the charge-discharge operation of CWDT pin is not performed.
____
8. WEN pin, WDI pin and W / T pin
___
Each of the WEN pin, the WDI pin and the W / T pin has a noise filter.
If the power supply voltage is 5.0 V, noise with a minimum pulse width of 200 ns can be eliminated.
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