This document describes the features and characteristics of the CAT803, CAT809, and CAT810 3-pin microprocessor power supply supervisors from Catalyst Semiconductor, Inc. It includes precision monitoring of +5.0V, +3.3V, +3.0V, and +2.5V power supplies, three output configurations, direct replacements for MAX803, MAX809, and MAX810 products, and suitability for applications operating over the industrial temperature range.