The TS809/810 series are microprocessor (P) supervisory circuit used to monitor the pow er 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 power ed circuits . These circuits perfor m a single func tion: they assert a reset s ignal whenever the VCC supply voltage declines below a preset threshold, keeping it asserted for at leas t 140ms after VCC has risen above the reset threshold. Reset thresholds suitable for operation with a v ariety of supply voltages are available. The TS809/810 series have push pull outputs. The TS809/809R have an ac tive low RESE T output, w hile the TS810/810R has an active high (R ESET) output. The reset comparator is designed to ignore fast 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 TS809/810 series ideal for use in portable equipment.