The MAX793/MAX794/MAX795 microprocessor (µP) supervisory circuits monitor and control the activities of +3.0V/+3.3V µPs by providing backup-battery switchover, among other features such as low-line indication, µP reset, write protection for CMOS RAM, and a watchdog (see the Selector Guide in the full data sheet). The backup-battery voltage can exceed VCC, permitting the use of 3.6V lithium batteries in systems using 3.0V to 3.3V for VCC. The MAX793/MAX795 offer a choice of reset threshold voltage range (denoted by suffix letter): 3.00V to 3.15V (T), 2.85V to 3.00V (S), and 2.55V to 2.70V (R). The MAX794's reset threshold is set externally with a resistor divider. The MAX793/MAX794 are available in 16-pin DIP and narrow SO packages, and the MAX795 comes in 8-pin DIP and SO packages.
Precision Supply-Voltage Monitor:
Fixed Reset Trip Voltage (MAX793/MAX795)
Adjustable Reset Trip Voltage (MAX794)
Guaranteed Reset Assertion to VCC = 1V
Backup-Battery Power Switching-Battery Voltage Can Exceed VCC
On-Board Gating of Chip-Enable Signals-7ns Max Propagation Delay