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