The TLV809 family of supervisory circuits provides circuit initialization and timing supervision, primarily for digital signal processors (DSPs) and processor-based systems. The newer TLV809E device is a pin-to-pin compatible alternative.
During power-on, RESET is asserted when the supply voltage (VDD) becomes greater than 1.1 V. 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(typ) = 200 ms) starts after VDD rises above the threshold voltage, VIT. When the supply voltage drops below the VIT threshold voltage, the output becomes active (low) again. No external components are required. All devices in this family have a fixed sense-threshold voltage (VIT) set by an internal voltage divider.
This product family is designed for supply voltages of 2.5 V, 3 V, 3.3 V, and 5 V. The circuits are available in a 3-pin SOT-23 package. The TLV809 devices are characterized for operation over a temperature range of –40°C to +85°C.