The TPS3803 and TPS3805 families of supervisory circuits provide circuit initialization and timing supervision, primarily for DSPs and processor-based systems.
The TPS3803G15 device has a fixed-sense threshold voltage VIT set by an internal voltage divider, whereas the TPS380301 has an adjustable SENSE input that can be configured by two external resistors. In addition to the fixed sense threshold monitored at VDD, the TPS3805 devices provide a second adjustable SENSE input. RESET is asserted in case any of the two voltages drops below VIT.
During power on, RESET is asserted when supply voltage VDD becomes higher than 0.8 V. Thereafter, the supervisory circuit monitors VDD (and/or SENSE) and keeps RESET active as long as VDD or SENSE remains below the threshold voltage VIT. As soon as VDD (SENSE) rises above the threshold voltage VIT, RESET is deasserted again. The product spectrum is designed for 1.5 V, 3.3 V, and adjustable supply voltages. The devices are available in a 5-pin SC-70 package.