ZHCSIK0A July 2018 – October 2021 TPS3430
PRODUCTION DATA
In this application, the window watchdog timing options are based on the PWM signal that is provided to the TPS3430. A window watchdog setting must be chosen such that the falling edge of the PWM signal always falls within the window. A nominal window must be designed with tWDL(max) less than 33.33 ms and tWDU(min) greater than 33.33 ms. There are several options that satisfy this window option. An external capacitor can be placed on the CWD pin and calculated to have a sufficient window. Another option is to use one of the factory-programmed timing options. An additional advantage of choosing one of the factory-programmed options is the ability to reduce the number of components required, thus reducing overall BOM cost. Leaving the CWD pin unconnected (NC) with SET0 = 0 and SET1 = 0 produces a tWDL(max) of 25.9 ms and a tWDU(min) of 46.8 ms; see Section 8.1.2.