The SP809/SP810 are low power microprocessor (μP) supervisory circuits used to monitor power supplies in μP and digital systems. They provide applications with benefits of circuit reliability and low cost by eliminating external components. If the VCC supply voltage falls below preset threshold then a reset signal is asserted for at least 140ms after VCC has risen above the reset threshold. Both the SP809 and SP810 were designed with a reset comparator to help identify invalid signals, which last less than 140ms. The only difference between them is that they have an active-low RESET output and active-high RESET output, respectively. Low supply current (1μA) makes SP809/SP810 ideal for portable equipment. The devices are available in 3 pin SOT-23 package.