The MAX817/MAX818/MAX819 microprocessor (P) supervisory circuits simplify power-supply monitoring, battery control, and chip-enable gating in P systems by reducing the number of components required. These devices are designed for use in +5V-powered systems. Low supply current (11A typical) and small package size make these devices ideal for portable applications. The MAX817/MAX818/MAX819 are specifically designed to ignore fast transients on VCC. Other supervisory functions include active-low reset, backupbattery switchover, watchdog input, battery freshness seal, and chip-enable gating. The Selector Guide below lists the specific functions available from each device. These devices offer two pretrimmed reset threshold voltages for 5% or 10% power supplies: 4.65V for the L versions and 4.40V for the M versions. The MAX817/ MAX818/MAX819 are available in space-saving MAX packages, as well as 8-pin DIP/SO.