SBVS301B October 2016 – September 2021 TPS3850
PRODUCTION DATA
The SET0 and SET1 pins can be used to control the window watchdog ratio of the lower boundary to the upper boundary. There are four possible modes for the watchdog (see Table 8-5): disabled, 1:8 ratio, 3:4 ratio, and 1:2 ratio. If SET0 = 1 and SET1 = 0, then the watchdog is disabled. When the watchdog is disabled WDO does not assert, and the TPS3850 functions as a normal supervisor. The SET0 and SET1 pins can be changed when the device is operational, but cannot be changed at the same time. If these pins are changed when the device is operational, then there must be a 500-µs (tSET) delay between switching the two pins. If the SET0 and SET1 are used to change the reset timing, then a reset event must occur before the new timing condition is latched. This reset can be triggered by SENSE rising above VIT+(OV) or below VIT-(UV), or by bringing VDD below VUVLO. Figure 7-7 shows how the SET0 and SET1 pins do not change the watchdog timing option until a reset event has occurred.