General Description
The MAX690 family of supervisory circuits reduces the complexity
and number of components required for power supply monitoring and
battery control functions in microprocessor systems. These include
µP reset and backup-battery switchover, watchdog timer, CMOS RAM
write protection, and power-failure warning. The MAX690 family
significantly improves system reliability and accuracy compared to
that obtainable with separate ICs or discrete components.
Benefts and Features
● Supervisory Function Integration Saves Board Space while Fully
Protecting Microprocessor-Based Systems
• Precision Voltage Monitor
- 4.65V (MAX690, MAX691, MAX694, MAX695)
- 4.40V (MAX692, MAX693)
• Power OK/Reset Time Delay
- 50ms, 200ms, or Adjustable
• Watchdog Timer
- 100ms, 1.6s, or Adjustable
• Battery Backup Power Switching
• Voltage Monitor for Power Fail or Low Battery Warning
• Minimum External Component Count
● Low Power Consumption in Battery Backup Mode Extends Battery Life
• 1µA Standby Current
● Onboard Gating of Chip Enable Signals Protects Against Erroneous
Data Written to RAM During Low VCC Events
Applications
● Computers
● Controllers
● Intelligent Instruments
● Automotive Systems
● Critical µP Power Monitoring