TPS3809K33DBVRG4 (TEXAS INSTRUMENTS)

The TPS3809K33DBVRG4 is a 3-pin Supply Voltage Supervisor that provides circuit initialization and timing supervision, primarily for DSPs and processor-based systems. During power-on, RESET is asserted when the supply voltage VDD becomes higher than 1.1V. Thereafter, the supervisory circuit monitors VDD and keeps RESET active as long as VDD remains below the threshold voltage VIT. An internal timer delays the return of the output to the inactive state (high) to ensure proper system reset. The delay time, td (typical) = 200ms, starts after VDD has risen above the threshold voltage VIT. When the supply voltage drops below the threshold voltage VIT, the output becomes active (low) again. No external components are required. This voltage supervisor has a fixed sense-threshold voltage VIT set by an internal voltage divider.