The TS803R are microprocessor (P) supervisory circuit used to monitor the power supplies in P and digital systems. They provide excellent circuit reliability and low cost by eliminating external components and adjustments when used with +5V, +3.3V, +3.0V powered circuits. These circuits perform a single function: they assert a reset signal whenever the VCC supply voltage declines below a preset threshold, keeping it asserted for at least 140ms after VCC has risen above the reset threshold. Reset thresholds suitable for operation with a variety of supply voltages are available. The TS803R are open drain outputs. The TS803R have an active low RESET output, while the TS803R has an active high RESET output. The reset comparator is designed to ignore fast transients on VCC, and the output guaranteed to be in the correct logic state for VCC down to 1V. Low supply correct makes the TS803R ideal for use in portable equipment. The TS803R is available in a 3-pin SOT-23 package.