General Description
The MAX817/MAX818/MAX819 microprocessor (µP) supervisory circuits simplify power-supply monitoring, battery control, and chip-enable gating in µP systems by reducing the number of components required. These devices are designed for use in +5V-powered systems. Low supply current (11µA 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, backup battery switchover, watchdog input, battery freshness seal, and chip-enable gating. The Selector Guide below lists the specific functions available from each device.

FEATUREs
♦ Precision Supply-Voltage Monitor:
   4.65V (MAX81_L)
   4.40V (MAX81_M)
♦ 11µA Quiescent Supply Current
♦ 200ms Reset Time Delay
♦ Watchdog Timer with 1.6sec Timeout (MAX817/MAX818)
♦ Battery-Backup Power Switching; Battery Voltage Can Exceed VCC
♦ Battery Freshness Seal
♦ On-Board, 3ns Gating of Chip-Enable Signals (MAX818)
♦ Uncommitted Voltage Monitor for Power-Fail or Low-Battery Warning (MAX817/MAX819)
♦ Manual Reset Input (MAX819)

APPLICATIONs
  Battery-Powered Computers and Controllers
  Embedded Controllers
  Intelligent Instruments
  Critical µP Monitoring
  Portable Equipment