The MAX791CPE+ is a microprocessor supervisory circuit in 16 pin DIP package. The MAX791 reduces the complexity and number of components 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 250mA output capability. The μP reset, manual-reset input and a 1.25V threshold detector provides for power-fail warning and low-battery detection or monitors a power supply other than +5V. Two-stage power-fail warning and a separate low-line comparator compares VCC to a threshold 150mV above the reset threshold. It features backup-battery switchover for CMOS RAM, real-time clocks, μPs or other low power logic. Software monitoring of backup-battery voltage. A watchdog-fault output is asserted if the watchdog input has not been toggled within either a preset or an adjustable timeout period. Write protection of CMOS RAM or EEPROM.
Supply voltage range is 0V to 5.5V
Operating temperature range from 0°C to 70°C
Precision 4.65V voltage monitoring
Power-OK/reset time delay is 200ms
Standby current is 1μA
Power switching of 250mA output in VCC modem and 25mA output in battery-backup mode
On-board gating of chip-enable signals of memory write-cycle & 6ns CE gate propagation delay
MaxCap or SuperCap compatible
Voltage monitor for power-fail or low-battery warning
