U5021M

The U5021M from Atmel is a digital window watchdog timer designed for critical safety applications. This CMOS integrated circuit monitors microcontroller activity by verifying cyclically transmitted trigger signals within a defined time window. A failure to receive a correct trigger signal prompts the watchdog timer to reset the microcontroller, ensuring system integrity.

This IC is suitable for microcontrollers operating in both full-power and sleep modes. It includes additional voltage monitoring features, such as power-on reset (POR) and supply voltage drop reset, providing a comprehensive monitoring solution for microsystems in automotive and industrial environments. The U5021M features low current consumption, typically less than 100 µA, making it energy-efficient. It operates with a stabilized supply voltage of 5 V ±5% and is available in an SO8 package.

Key features include an RC oscillator, internal reset during power-up and supply voltage drops, and distinct trigger windows for active ('short') and sleep ('long') modes. It also supports cyclical wake-up of the microcontroller in sleep mode, a trigger input, a single wake-up input, a reset output, and an enable output. The enable output is activated after three correct processor triggers, useful for controlling peripheral components.