S-19400 Datasheet, PDF (16/36 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
2. From reset release to initiation of charge-discharge operation to CWDT pin
The charge-discharge operation to the CWDT pin differs depending on the status of the WEN pin at the reset release.
2. 1 When WEN pin is "H" at reset release (Active "H")
Since the watchdog timer is Enable, the S-19400/19401 Series initiates the charge-discharge operation to the
CWDT pin.
VDD
CPOR
CWDT
WEN
(Active "H")
WDO
RST
(S-19401 only)
Figure 26 WEN Pin = "H"
2. 2 When WEN pin is "L" at reset release (Active "H")
Since the watchdog timer is Disable after the CPOR pin performs the charge-discharge operation 4 times, the
S-19400/19401 Series does not initiate the charge-discharge operation to the CWDT pin. If the input to the WEN
pin changes to "H" in this status, the S-19400/19401 Series initiates the charge-discharge operation to the CWDT
pin.
VDD
CPOR
CWDT
WEN
(Active "H")
WDO
RST
(S-19401 only)
Charge-discharge operation is initiated
at WEN pin = "H"
Figure 27 WEN Pin = "L" → "H"
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