The TS803/TS803R are microprocessor ( P) supervis ory circuit used to monitor the power supplies in P and digital systems. They provide excellent circuit reliability and low cos t by eliminating external components and adjustments when used with +5V, +3.3V, +3.0V powered circuits. These circuits per form a single function: they assert a reset signal whenever the VCC supply voltage declines below a preset threshold, keeping it asser ted for at least 140ms after VCC has risen above the reset threshold. Res et thresholds suitable for operation w ith a variety of supply voltages are available. The TS803/TS803R are open drain outputs. The TS803/TS803R have an ac tive low RESE T output, while the TS803/TS803R has an active high R ESET output. The reset compar ator is des igned to ignore fas t transients on VCC, and the output guaranteed to be in the correc t logic state for VCC dow n to 1V. Low supply correct makes the TS803/TS803R ideal for use in por table equipment.