In automotive microcontroller or microprocessor power-supply applications, the watchdog is used to monitor the microcontroller working status to prevent software runaway. It is necessary for the watchdog to be independent of the microcontroller in a reliable system.
The TPS7B68xx-Q1 device is a family of 500-mA watchdog LDOs designed for an operating voltage up to 40 V, with typical quiescent current of only 19 µA at light load. The devices integrate a programmable function for selecting a window or standard watchdog, with an external resistor to set the watchdog time within 9% accuracy.
The PG pin on the TPS7B68xx-Q1 devices indicate when the output voltage is stable and in regulation. The power-good delay period and power-good threshold can be adjusted by external components. The devices also feature an integrated short-circuit and overcurrent protection. The combination of such features makes these devices particularly flexible and suitable to supply microcontroller systems in automotive applications.