ZHCSIJ8A July 2018 – October 2021 TPS3431-Q1
PRODUCTION DATA
As illustrated in Figure 8-1 there are three options for setting the watchdog timer. The design specifications in this application allow for a factory-programmed timing option by leaving CWD floating. To ensure proper functionality, a falling edge must be issued before tWD(min) with is set for 1.36 seconds when CWD is not connected. Figure 8-8 illustrates that a WDI signal with a period of 1 second keeps WDO from asserting.
Figure 8-4 shows WDO asserting when the WDI signal has a period longer than tWD(max) which is 1.84 seconds when CWD is not connected. Figure 8-5 shows a watchdog fault caused by missing WDI pulse followed by correct timing WDI pulses to deactivate WDO.