The MAX691A/MAX693A/MAX800L/MAX800M microprocessor (µP) supervisory circuits are pin-compatible upgrades to the MAX691, MAX693, and MAX695. They improve performance with 30µA supply current, 200ms typ reset active delay on power-up, and 6ns chip-enable propagation delay. Features include write protection of CMOS RAM or EEPROM, separate watchdog outputs, backup-battery switchover, and a RESET-bar output that is valid with VCC down to 1V. The MAX691A/MAX800L have a 4.65V typical reset-threshold voltage, and the MAX693A/MAX800M's reset threshold is 4.4V typical. The MAX800L/MAX800M guarantee power-fail accuracies to ±2%.