MAX791 Datasheet | Maxim Integrated

Description The MAX791 microprocessor (µP) supervisory circuit reduces the plexity and number of ponents needed to monitor power-supply and battery-control functions in µP systems. The 50µA supply current makes the MAX791 ideal for use in portable equipment, while the 6ns chip-enable propagation delay and 250m A output capability (25m A in battery-backup mode) make it suitable for larger, higher-performance equipment. The MAX791 es in 16-pin DIP and narrow SO packages and provides the following functions: - - - - - - 1) µP reset- RESET output is asserted during power-up, power-down, and brownout conditions, and is guaranteed to be in the correct state for VCC down to 1V, even with no battery in the circuit. 2) Manual-reset input. 3) A 1.25V threshold detector provides for power-fail warning and low-battery detection, or monitors a power supply other than +5V. 4) Two-stage power-fail warning- a separate low-line parator pares V CC to a threshold 150m V above the reset threshold. 5) Backup-battery switchover for CMOS RAM, real-time clocks, µPs, or other low-power logic. 6) Software monitoring of backup-battery voltage. 7) A watchdog-fault output is asserted if the watchdog input has not been toggled within either a preset or an adjustable timeout period. 8) Write protection of CMOS RAM or EEPROM. 9) Pulsed watchdog - - - - output, to give advance warning of impending WDO assertion caused by watchdog timeout. ____________________________Features o o o o o Precision 4.65V Voltage Monitoring 200ms Power-OK / Reset Time Delay Independent Watchdog Timer- Preset or Adjustable 1µA Standby Current Power Switching 250m A Output in VCC Mode 25m A Output in Battery-Backup Mode On-Board Gating of Chip-Enable Signals Memory Write-Cycle pletion 6ns CE Gate Propagation Delay Max Cap or Super Cap patible Voltage Monitor for Power-Fail or Low-Battery Warning Backup-Battery Monitor - - - - - - Guaranteed RESET Valid to VCC = 1V MAX791 o o o o o ‰ ‰ ______________Ordering Information PART...