Datasheet

LTC2938/LTC2939
9
293839ff
TIMING DIAGRAM
V
n
Monitor Timing
Reset and Watchdog Timing
V
n
RST
WDO
WDI
293839 TD02
t
RST
t
RST
t
RST
t
RST
t
RST
t
RST
t
RST
t
WD
t
WD
t
WD
t
WD
POWER-ON RESET
FOLLOWED BY RESET
CAUSED BY
UNDERVOLTAGE EVENT.
WATCHDOG OUTPUT SET
HIGH, WATCHDOG INPUT =
DON’T CARE
WATCHDOG INPUT NOT TOGGLED,
WATCHDOG TIMER EXPIRES, WATCHDOG
OUTPUT PULLS LOW. RESET OUTPUT
PULLS LOW FOR ONE RESET TIMEOUT
PERIOD.
WATCHDOG INPUT REMAINS UNTOGGLED,
WATCHDOG OUTPUT REMAINS LOW,
RESET OUTPUT PULLS LOW AGAIN AFTER
ONE WATCHDOG TIMEOUT PERIOD.
WATCHDOG OUTPUT CLEARED BY
UNDERVOLTAGE EVENT.
WATCHDOG INPUT NOT
TOGGLED, WATCHDOG
TIMER EXPIRES,
WATCHDOG OUTPUT
PULLS LOW. RESET
OUTPUT PULLS LOW.
WATCHDOG OUTPUT
LOW TIME SHORTENED
BY UNDERVOLTAGE
EVENT DURING RESET
TIMEOUT.
WATCHDOG INPUT NOT
TOGGLED, WATCHDOG
TIMER EXPIRES, WATCHDOG
OUTPUT PULLS LOW. RESET
OUTPUT PULLS LOW.
WATCHDOG OUTPUT NOT
CLEARED BY WATCHDOG
INPUT DURING RESET
TIMEOUT. AFTER RESET
COMPLETED, WATCHDOG
INPUT CLEARS WATCHDOG
OUTPUT.
t
RST
293839 TD01
V
RT
V
n
RST
t
UV