MAX690A/MAX692A/ MAX802L/MAX802M/ MAX805L
Microprocessor Supervisory Circuits
General Description
The MAX690A/MAX692A/...
MAX690A/MAX692A/ MAX802L/MAX802M/ MAX805L
Microprocessor Supervisory Circuits
General Description
The MAX690A/MAX692A/MAX802L/MAX802M/MAX805L reduce the complexity and number of components required for power-supply monitoring and batterycontrol functions in microprocessor (μP) systems. They significantly improve system reliability and accuracy compared to separate ICs or discrete components.
These parts provide four functions:
1) A reset output during power-up, power-down, and brownout conditions.
2) Battery-backup switching for
CMOS RAM,
CMOS μP, or other low-power logic.
3) A reset pulse if the optional watchdog timer has not been toggled within 1.6s.
4) A 1.25V threshold detector for power-fail warning or low-battery detection, or to monitor a power supply other than +5V.
The parts differ in their reset-
voltage threshold levels and reset outputs. The MAX690A/MAX802L/MAX805L generate a reset pulse when the supply
voltage drops below 4.65V, and the MAX692A/MAX802M generate a reset below 4.40V. The MAX802L/MAX802M guarantee power-fail accuracies to ±2%. The MAX805L is the same as the MAX690A except that RESET is provided instead of RESET.
All parts are available in 8-pin DIP and SO packages. The MAX690A/MAX802L are pin compatible with the MAX690 and MAX694. The MAX692A/MAX802M are pin compatible with the MAX692.
Applications
●● Battery-Powered Computers and Controllers ●● Intelligent Instruments ●● Critical μP Power Monitoring
Typical Operating Circuit
UNREGULATED DC 0.1µ...